Since women and men differ in so many ways, why not expect differences in how and why they form kidney stones? They do differ, and in ways that can matter as we try to prevent new stones and think about what is most likely to work best for each. The haunting and beautiful “Isaac and Rebecca”, Known as ‘The Jewish Bride’, Rembrandt van Rijn, c. 1665 – c. 1669, oil on canvas, hangs in the Rijksmuseum, Amsterdam. Despite many speculations as to the subjects, including the biblical one at the museum site, experts have failed to reach a consensus. Old News We have known a few differences for a while now, so before I tell you what is new let’s … Continued
Browse the Video Collection. All of the site videos are here, standalones and those that belong to special articles.
Gerard Dou, a Dutch painter and draughtsman (1613 – 1675), painted The Dropsical Woman in oil on panel in 1663. It is cataloged in the Louvre under Vermeer and the masters of genre painting.
Of highest importance, this article tells what is known about the increased pregnancy risks of stone forming women. These include gestational diabetes, premature delivery, spontaneous abortion, hypertension, and preeclampsia. Obversely, pregnancy is a stone forming condition because of high urine calcium and pH, and relatively low urine citrate, so more pregnancies raise risk of stone formation. A lot can be done to help, and that is why I wrote this article.
If you make stones, your renal papillum is abnormally dense when seen on a CT scan. Physicians can measure that density. It is not the stones, it is the tissue itself, and many think the density reflects the plaque and plugging stones form over. It is in both kidneys, even if only one kidney has formed a stone, and is present on CT scans made before people ever formed a stone. Presumably plaque and plugs come before stones. One year of an extra 2 liters of fluid a day reduced the density to normal. Possibly fluids dissolve plaque and plugs. Possibly it is something else. Whatever the reason, fall in density can tell you your fluids have been higher on average – a good gauge of how stone prevention is going.
This disease is not uncommon as a cause of calcium stones, and because curable most important to recognize promptly. This article is the easier of two I wrote, and I am afraid it has nevertheless been difficult for patients, forbidding, and therefore not as useful as I had wanted. I have produced a video for it that makes the main points much clearer. I did it in hopes that anyone with even a suspicion of the disease seeks and obtains diagnosis and cure. The video is chatty but under it all rigorous enough to guide people toward what they need.
Red meat does not raise kidney stone risk – that is what this article says. Veggies lower stone risk. Dairy protein is in between, a minor protection. You might have thought otherwise. After all doesn’t everyone know red meat is bad for you? Well, for stones it is not a problem. That massive protein loading might raise risk – we are talking about protein powders and bars – was not tested in the work here, so I can say it is not a good idea but cannot prove it. The protective power of veggies comes from their potassium alkali content, a bit like the food version of potassium citrate. Also, veggies have a high water content, so urine volume goes up. I made a video for this article because a patient wrote in and asked for one. She had seen an older version. I told her I would do the video, and while I was at it I made the article a lot better than the original.
If you make these stones, this is your core article. I added two videos – comprehensive (19 minutes), summary (10 minutes) to make it as accessible as possible. It tells about why calcium phosphate stones form and the complexities of their prevention. Likewise, it details the kidney damage from these stones, and possible risks imposed by shock wave lithotripsy. I intended it foremost for patients, but it has the kind of detail physicians and scientists also need. The article on brushite supersaturation was written to complement this one, but I fear the title has put everyone off from looking at it.
Calcium phosphate (CaP) supersaturation shown on every modern 24 hour urine panel is actually supersaturation with respect to brushite, a crystal you may not even have heard of. But it forms in you, in your kidney tubules and urine. Science has shown us that brushite forms before the big stars of stone disease, calcium oxalate and hydroxyapatite, and probably triggers off their formation. Like tinder for a fire, supersaturation its match, brushite gets things started and is consumed in the process so we rarely speak about it. As basic science predicts, risk of stone disease increases as brushite supersaturation rises above 1; for calcium oxalate supersaturation the first onset of risk is at 3 or more. So it seems smart to push our stone prevention enough that brushite supersaturation (alias CaP SS) goes below 1. Risk – zero. Probably benefit – Yes. Why not?
If you have read about ‘Big Data’, you have read about empirical research. Likewise if you were around when we sent people and robots to the Moon to collect samples, or watch movies about deep sea exploration, or historicals about mapping the ocean sea, or nature movies about collecting plants in the Amazon. The purpose is to collect facts about the world as it is, meaning some sample more or less unaffected by selection biases so as to get a clear picture of things in relation to one another – what is the Moon made of? What is the sea bottom like right here? How can I sail from here to there? Which species grow there? The front line people may not fly in rocket ships, or dive, and certainly the seas have been mapped for sailing in – often only a few are adventurers, the majority just thinkers and number crunchers. But it is not the pursuit of a small band of dreamers – more industrial, more workflow oriented, professionalized to absolute. Without the facts, what do we dream up inventions from, new treatments, new tests? And as for dreaming about how the world got the way it is, out of the question. In our little world, empirical science is how we know that urine calcium, or oxalate, or volume, or citrate, or supersaturation are graded stone risks, or that stone formers are more prone to cardiovascular and bone disease.
Do not run away, do not click elsewhere. Read this. Patients most of all need to judge for themselves about the quality of what science has offered to them by way ot diagnosis and treatment. How can you judge without some idea about how science works? I have made a set of videos specially for patients to introduce science as something elaborate but essentially not so foreign you cannot understand what is done, and why. Each video has a range from easily accessible to something more, so everyone can learn something, perhaps not all. Take a look, spend ten minutes. Educate yourself so you can better judge what is told to you, offered to you. So you can look at what evidence there is, and have some basis for estimating its reliability.
If diet changes to prevent stones have exceeded your imagination and your patience, here is a collection of recipes aimed precisely at the main diet goals: less sodium, protein, sugar and oxalate, more calcium and potassium. Their creator is a well certified medical nutritionist, so the quantities will be right. She is a lifetime cook and foodie, so one hopes these items taste as good as they are correct in their composition. Whether you or your family will like them is unknown until enough of you try them and let us know what you think.
Small stones pass in hours sometimes, a few days, perhaps. But some take a longer time and can obstruct the kidney as they pass. Stones at the upper edge of ‘passable’ may take longer, but one hopes to avoid a surgery. As they pass, if the stone is obstructing the kidney, how long can one wait without risk of injuring the kidney? As I wrote this article I found very few human studies of this important matter. Animal studies are numerous but I doubt they properly model what happens in humans. Obstruction reduces the function of a kidney, and that function returns to normal if relief is rapid enough. But let too much time elapse and function may not return to normal. Kidney tissue is lost if obstruction persists too long. So the issue is how long is safe? I did my best here to help place that interval. My conclusion is we have enough to make a reasonable decision now but we much need more human data.
When stones are large, either individually or as a mass of smaller stones, ureteroscopic removal may become impractical and shock wave lithotripsy as well. Both leave an excess of residual stone fragments behind. PERC offers a stone free kidney in return for a more taxing surgery. I find that few patients really know what PERC entails. Here, Dr Luke Reynolds has made the facts clear in a lucid text and with well selected pictures. We already have an excellent article on ureteroscopy, and now with this article the site is reasonably complete with regard to stone removal.
This is the main disorder in stone forming patients and I have rewritten the old article into a totally new one. I also made a video for it. The kidney stone diet, the role of sodium and calcium in bone preservation, all these are related to IH. The new article is much finer than what I had, and adds new knowledge we have accumulated. The video is helpful.
Aimed at families of children with stones, this article covers the basics: Recurrence of stones, 24 hour urine testing results from a large study, and advice about treatment. I cannot cover surgery for children as I am not a surgeon but hope to find someone who is and will. Likewise I have not as yet written about the many rare genetic causes of stones in this group.
If you form calcium kidney stones not due to a systemic disease, so called idiopathic calcium stones, in other words if you are in the vast majority of stone formers, this article is for you. It pulls together in one place the instructions for casting a magic spell to stave off stones without medications. LIke all spells, it must be done exactly. Like most, it can cause harm if done wrong. It is a three fold effort at diet change that is the heart of the kidney stone diet, but often lost in the complexities of that diet. Of all you can do, beside drink enough fluids, this threefold is premier, dominant, necessary. Read it, do it – carefully.
This is an article about one extreme of a range, about people whose stones start later than the average. Those people have a higher risk of forming uric acid stones, so stone analysis is paramount. They are more prone than in youth to have primary hyperparathyroidism as a cause. Bone disease may have gone unnoticed. It is not a long article and this is not a long introduction. But it is an important matter for the late comers.
Among the defects of the modern diet, acid load is rather obscure yet possibly as dangerous as more famous risk factors, like sodium excess. Acid loads are thought to cause bone disease, hypertension, glucose intolerance, and loss of muscle in later years. Meats, eggs, milk, things we need to eat, create acids in our bodies. Fruits and veggies produce alkali. So a balanced diet can be nutritious and at the same time safe in that acids are neutralized by food alkali. Alas, on balance, the Western diet mostly creates an acid load. Women choose better than men. They better balance their acid foods with alkali foods. But unknown to all of us until recently, women do something else that undoubtedly benefits them. Eating the very same foods as men, they take up more of its alkali. Whatever acids the food has are balanced by that extra alkali. As a result, women protect themselves against food acid better than men do. They choose better and their biology help, too. The downside is a more alkaline urine and therefore a greater tendency to form calcium phosphate stones. All this means that women and men are very different. Balancing diet acid and alkali is more urgent in men, allowing for a more alkaline urine more urgent in women.
We know that forming stones marks one as more susceptible than average to cardiovascular, renal, and bone disease, but we do not know why. We also know that the modern and rather unhealthy US diet promotes all of these diseases, including stones themselves. If we put these facts together with one other, we get what I call a workable idea of what is going on. The one other is this: Not everyone is susceptible to diet induced diseases. So perhaps – this is my new thought – being susceptible to one of them, stones, means being susceptible to them all. That would explain why stone forming raises so many otherwise inexplicable risks, and also lead to a simple but powerful conclusion – always do everything possible with diet to prevent stones, even if one also needs meds and high fluids. Diet change is an effective stone prevention but difficult to achieve. If stone forming means it is especially important to stave off cardiovascular, renal and bone disease, we should all work even harder to use healthy diet as the foundation of stone prevention. I say in advance this is a new thought, unproved if intriguing and in accord with known facts. Science can and will test it, but in the meantime how much better to go to some trouble with a safe if difficult diet change than to look back with regret we did not.
New stone counts tell if your treatment is a success or failure. Success means new stones are fewer and less often. But is that stone new or not? Your physician is the ultimate authority, but you can help so much that the value for your care is above rubies. A new stone is passed or removed or on an image – CT, flat plate, ultrasound – and not present on a prior image. Sounds simple, and it is if all the dates and images are available. But physicians are very busy, their time much taxed by modern practice demands. You can invest much more time getting everything together. When did each of your stone events happen? Where are the reports, the images? If you pull them into a convenient form, and do everything you can to ascertain if stones were new or not, your physician can easily finish the job, refine the count, and say if things are really going well, or not. Read this, and do what you can to help.
This article describes the two current theories about how plaque forms, and shows a critical test of one theory – vas washdown. This theory holds that plaque forms because of tissue supersaturations and therefore what we do to prevent stones – fluids, the kidney stone diet, thiazides or potassium citrate – should serve to reduce plaque. That it has survived a critical test means we should proceed clinically with vas washdown in mind. Likewise, the successful test of vas washdown could plausibly lead to a trial asking if common stone preventions reduce plaque. No plaque reduction trials have been done so far. The other theory has it that kidney cells transform to bone like cells which make plaque as bone would. It probably would lead to different kinds of prevention. In one study, a search for bone gene expression in regions of plaque was negative.
Especially among younger women epidemiologists have demonstrated increased risk of these dangerous diseases among stone formers. Why stone forming raises risk of vascular disease is not known nor whether stone prevention helps stave it off. But we now understand that forming stones means increased risk across a wide range of diseases – bone disease, high blood pressure, kidney disease, and now stroke and heart attack. It does make clear that all stone formers need special and significant medical attention, and that just ‘drink a lot of water’ is as silly an admonition as it is potentially dangerous. Stone patients need serious and thoughtful medical attention, and not just to their stones.
No, you do not need to restrict your intake of animal protein. It does not cause your kidney stones unless you eat it in great excess. That is what this excellent new research tells us. If you stay in the usual range of 0.8 – 1 gm protein/kg/day – the range recommended for everyone in the US, animal protein intake has no effect on risk of new onset kidney stones. So, do not believe that protein restriction, or restriction of red meat will prevent stones. The other side is different; excesses of protein – protein shakes, huge steaks, high protein/low carb diet regimens, all of these could be risky. This new study does not tell us anything definite about excesses. Better to avoid extremes.
Fruits and veggies, our sources of potassium, are a perfect goodness. More and more cause lower and lower rates of kidney stone onset. Eat them in excess, if you want. But even here, I have a warning. When you take these foods apart – think smoothies, blenders – you can get in one glass the juice from – as an example – 8 oranges and all their extra fructose and oxalate. So, eat food, not extracts, and of these – the fruits and veggies – partake liberally. The US recommended is 4,000 mg of potassium, from five servings of fruits and veggies every day. Eat them.
This is not new to the site. The kidney stone diet has precisely these amounts of meats and veggies. But this new science bolsters our recommendations, gives them a more powerful force, a securer base.
AWAITING COMPOSITION INFORMATION FROM SELLERS Considerable scientific research supports the idea that urine citrate reduces crystallization of calcium kidney stone salts. The research includes two prospective double blind controlled kidney stone prevention trials. Citrate binds calcium, reducing the fraction free to bind with oxalate or phosphate. Citrate inhibits formation and growth of calcium stone forming crystals. Almost certainly, brushite or octocalcium phosphate crystals help initiate calcium oxalate crystallization in urine, and citrate strongly inhibits that process. Kidney cells control how much citrate is in the urine. Blood concentration is high enough that large amounts of citrate are filtered, but much of the filtered citrate is reabsorbed back into kidney proximal tubule cells that metabolize it for energy. The reabsorption of filtered … Continued
Let me put the main points first, so you know what you are going to read about. Kidney stone formers have increased pregnancy risks for prematurity, need for C-section, low birth weight newborns, gestational diabetes, and preeclampsia. To write about all this I did a PubMed search: “Pregnancy AND kidney stones” which yielded 357 papers published between 1962 and 2021 – a surprisingly small collection. Many are reviews, guideline statements, or specialized beyond the uses of this article. From the lot, I selected 25 with original data, of which I use those few that concern risks to mothers and their fetuses. I use additional references about preeclampsia risks unrelated to kidney stones. The detail from the gorgeous Arnolfini Portrait, Jan Van … Continued
VIDEO ARTICLE: Watch it or read it. The title is my story’s conclusion. We know that calcium phosphate crystals in plaque, plugs, and the vast majority of stones are hydroxyapatite, yet when we measure supersaturation with respect to calcium phosphate we measure that for brushite, the pretty crystal in the big image that begins this work. We do it because brushite crystals may initiate calcium oxalate stone disease, so it is wise to prevent their forming. The beautiful image is a hand colored electron micrograph of brushite crystals by Kseniya Shuturminska. I have written about brushite on this site before, but this crystal is so important yet buried in that eerie world where atoms and molecules combine, it seemed to … Continued
Empirical science is ancient beyond imagining, for it is nothing more than the modern version of exploring to find out what is there. Don’t you do it after checking in to the hotel in a city new to you? Go out on the streets and see what is going on, where things are? How people dress, what there is to do? This video, the second in the series, tells about this most reliable and fundamental branch of research science. The first video in this series, the one that preceded this one, tells about all three branches of science, and is useful here as background. The featured image that depicts the death of Captain James Cook, painted by Johan Joseph Zoffany … Continued
As much as diet causes kidney stones, diet change prevents them. Not diet in general, of course, too vague to matter. Thus far decent science identifies only seven components of diet as affecting stone formation: calcium, sodium, refined sugars, potassium, protein, oxalate and high fluids of the proper kinds. A diet correct for the first five components corresponds with present day healthy diet recommendations for all people in the US. Everyone should eat it. Oxalate control and high fluids are specific to stones, however, so all seven components combined is properly named the “kidney stone diet”. The featured picture shows a new collection of recipes by Melanie Betz that address, excluding fluids, all components of the kidney stone diet. It … Continued
Our site is fortunate that Dr. Luke Reynolds, an outstanding young urological surgeon, has created an article on percutaneous nephrolithotomy (PCNL). Many patients come to need this complex surgery, and most will not know much about it. An article about PCNL has long been missing and I am thrilled this talented and experienced surgeon has been willing to write it for us. Fred Coe The lovely photograph of autumn’s gourds is by Phyllis Brodny, a contemporary artist to whose eyes these natural shapes display startlingly human attitudes. This image is from the cover of her book of gourds pantomiming life, the commonplace and the wonderful. Origins of PCNL Before the 1970’s patients suffering from kidney stones required open surgery. In … Continued
These videos seems very popular and so I have collected all of them in one place so people can find them easily. Some are part of written articles, and essentially walk through the articles and explain what is said. Others are free standing and more elaborate. I confess that video making is a bit new to me, so these are not perfect. But I have lectured for decades and have a reasonable grasp of how to communicate, so if the technique could be better the narrative seems to me pretty good most of the time. This is the growth area of the site, so it will enlarge rapidly. The wonderful picture is by Laurentius de Voltolina (Florence, 1300’s). It hangs … Continued
Pieter Bruegel the Elder (1530-1569) painted ‘Children’s Games’ in 1560. It resides in the Kunsthistorisches Museum, Vienna. Video: Stones in Children On the Rise If you read the many reviews that abound (Pediatr Ann. 2017;46(6):e242-e244; Bowen D K Urol Clin N Am 45 (2018) 539–550; Evaluation and Medical Management of Kidney Stones in Children 2014) they mostly all say the same things. Stones are becoming more frequent among children and adolescents. Generally children form calcium stones, as do adults. They benefit from the same surgical procedures as adults but their smaller size demands specialized skills. Genetic causes of stones tend to manifest earlier in life and are therefore enriched among children. What seems unique to children is their stone risk … Continued
Of all the knowledge on this site, a tiny nugget of three well established facts has explosive power for patients and physicians. Put to actual use they let you prevent idiopathic calcium stones and preserve bone mineral. If you do not want to read the article, I have made a VIDEO to tell you the story in about 13 minutes. On my iphone the video opens well and looks better horizontal. Please let me know if it does not work well for you. I have not been shy nor secretive. Article after article speak about the three, but always in context so other facts can distract one, as can superb but unmagical paintings from a few masterpieces hung on the … Continued
VIDEO Middle age 45 – 65, not the usual time to form your first kidney stone. The average for new stone onset is 35, with a spread of about 12 years, so by 45 you might think the odds are in your favor. But not always. Sometimes they start late, even into your fifties or sixties. It doesn’t matter some of the time. A stone is a stone. But older people get stones for a different spectrum of reasons than when young, so you have to think a bit about why. The image, a self portrait by Jan van Eyck (1390-1441), was painted in 1433 in oil on panel. It hangs in the National Gallery, London. This article is co-authored … Continued
We have known for a long time that phosphate stone formers are mainly women. We also have long known that phosphate stones form when urine is more alkaline, and that women produce a more alkaline urine than men. So the fact of phosphate stones being more in women seemed a consequence of their physiology. But why? Why do women have this physiology, this alkaline urine? Have it so consistently they form calcium phosphate stones as geological relics? If asked, most would say women do this because of how they eat. Compared to men women eat more veggies, a source of alkali, and less meats – a source of acid. More alkali in their diets, a more alkaline urine, phosphate stones, … Continued
The painting by van Gogh, The Sower with Setting Sun (1888) Kroller – Muller Museum, Otterlo, Netherlands, has no obvious connection to this article unless you have read Nellie Hermann’s essay on the former mining district of Belgium called the Borinage. Writing in the Paris Review, she reminds us van Gogh lived there in the 1880’s amidst active coal mines now long obliterated. He based his painting on an earlier (1850) painting, The Sower by Jean-François Millet (1814–1875). The artist sold it in 1851 to William Morris Hunt (1824-1879), Boston, where in 1917 Quincy Adams Shaw, Jr. (who inherited it) and Mrs Marian Shaw Haughton donated it to the Boston Museum of Fine Arts where it resides. It seems unlikely van Gogh ever saw the original but … Continued
The aims of stone prevention are to reduce the number of new stones formed, and to reduce the growth of stones in kidneys by lowering supersaturation. This means we gauge our success by counting and measuring stones. Mostly, radiologists measure and we count. That is why I wrote this article. Ultimately, physicians are responsible for counting, but patients can help a lot. Moneylender and his Wife (Quentin Massys, 1465 – 1530), painted in 1514, hangs in the Musee du Louvre, Paris. Massys was ‘…the first important painter of the Antwerp school.’ How To Count New Stones New vs. Pre-existing A stone passed or removed or found in an image, and not present on a prior image, is a new stone. Therefore all … Continued
I put my youngest image here because the groundwork of what I offer belongs to 1965 when I first thought about the problem and 1968 when my paper about it was published. I should have put in as a bookend my latest and oldest image, too, for I completed the thought just last summer. The thought is about clearance, the very foundation of all renal physiology, and how I have always had it wrong, or perhaps better said, had an incomplete view of it. Probably most of us have done just fine with that incomplete view. But I mean to show you that traditional clearance and its practical uses are a limited version of what nature has to tell us. … Continued
The white clouds you can easily see on this human papillum are Randall’s plaque, named for the man who first described them. Stones grow on them. You can find bits of plaque and on such stones where they were once attached. Because plaque forms in and lies in the renal papillary tissue itself, bits of plaque on stones often carry with them fragments of tubules. This site has a long article detailing what we know about the facts of plaque, and rather than repeat it here is the link. But how does this plaque come to be? Who Would Care? Scientists, of course. They measure things and imagine how they got the way they are. Then measure again to see if they … Continued
In other articles I have reviewed evidence associating kidney stones with high blood pressure and kidney disease. One might well extrapolate from these two associations that stone forming will also associate with vascular complications such as stroke and myocardial infarction. High blood pressure and kidney disease are well known risk factors for both. In fact, this is true. Forming stones associates with higher risk of both stroke and acute myocardial infarction (AMI) – commonly called heart attack – when compared to people free of stones. These associations do not say that stones themselves cause high blood pressure, or stroke, or AMI, merely that people who form them have higher risks of vascular disease leaving unsaid what might be the matrix of … Continued
The title accurately reflects the pragmatic value of the new research I review here. This work shows, for the first time, how one can use urine supersaturation measurements as an estimate of kidney stone risk. It also tests more rigorously than any study to date the urine supersaturation hypothesis that places supersaturation in a position of high primacy in kidney stone formation. That test supports the primacy of supersaturation, and at the same time shows us how to use supersaturation as a graded risk factor, in the same way we use urine calcium, oxalate, citrate, and volume. I wish to thank Drs Gary Curhan (Harvard) and John Asplin (Litholink) for their careful review and corrections to this article. The beautiful … Continued
The web is majestic and grand, but filled with mixtures of good and bad reporting and advice. Here I have picked out of a simple Google search – kidney stones – some sites I can recommend. For these I try to make clear what I see in them as well as limitations. kidneystoners.org The featured site, though not ‘.edu’ is in fact a university level site run by distinguished experts and thoughtful patient advocates. It has a lot of patient content as well as medical materials, and the quality is very high. Dr Mike Nguyen, Associate Professor of Clinical Urology at the Keck School of Medicine of USC in Los Angeles, CA, founded this site years ago and it has … Continued
Bariatric surgeries can injure kidneys by raising urine oxalate excretion. This latter causes kidney stones, and raises risk of acute and chronic oxalate nephropathy. Overall, their benefits far outweigh these risks, especially when patients and physicians take proper precautions.But risk lurks as if in shadows, and waits on accident. The patient here inadvertently raised her risk of injury. Like all instances this one is just that: Opportunity to inspect the details of an undesired outcome so as to reduce the chance it will happen to others. The kidneys of anyone with increased urine oxalate excretion could be injured as her’s were, so common are the causes, so seemingly innocuous. The high resolution scan of a kidney from a child with primary hyperoxaluria … Continued
Watch the Video Gary Curhan and Eric Taylor have given us many insights into how diet might influence kidney stone risk. I think this new article by them and their colleagues a great opportunity for close reading and practical use of a high quality research paper remarkably germane to the practice of kidney stone prevention. What They Want We all know that science is about discovery that enables us to do something, or know how nature does something. As a consequence, most of us ask what kind of science a paper is about – doing or knowing. But we also all know that this dichotomy is false because almost every scientist is after at least some of both. Likewise, that a paper lies … Continued
Unfortunately producing stones means higher risk of hypertension and kidney disease. But most of the diet changes and even first line medications for stone prevention also lower blood pressure. Here is how that works. The featured painting, Vincent Van Gogh, The Starry Night. 1889. Oil on canvas hangs in The Museum of Modern Art, New York. Somehow, to me, the whorles of color bring blood pressure to mind. Some say the yellow halos about objects came from digitalis excess, from his physician. My Sources From time to time, quantitative scholars produce ‘guidelines’ about diagnosis and treatment of disease. Recently, a band of such have compiled results from the large literature on blood pressure treatment and given us this new compendium. For … Continued
Elsewhere we have described an innovative web based course aimed at reducing kidney stone risk factors via improved diet. Briefly, the course helps patients whose physicians have prescribed diet and fluid changes implement those changes, by teaching them to choose the right foods and fluids. We have articulated the underlying science of the kidney stone diet upon which the course is based. The powerful innovative element is that the course lives online, so it can present itself to patients via social media and websites, and patients can access it world wide. Likewise, costs can be very modest compared to conventional dietician visits because much of the work is group based and requires no fixed overhead for space. But however innovative it may … Continued
This may be the most important article – to me – I have written thus far. It is a plea and argument that stone patients need more from us than prevention of stones, because often enough they harbor significant diseases that associate with stone forming and require their own treatments. We need to treat the patients, not just their stones. The magnificent Garden of Earthly Delights (Hieronymus Bosch, 1450 – 1516) hangs in the Prado. I chose it here as it contains the whole world, which is to say that every patient is that self same. Stone Formers Have Other Disease Risks When you look at the data, kidney stones belong to a manifold of diseases that run together: Bone … Continued
Gary Taubes has written a substantial and important book summarizing the evidence that table sugar is a toxin. In this article, from Aeon, Taubes summarizes his thoughts and marshals the evidence in a highly readable and convincing form. Briefly, he dismisses the older idea that sugar – through its calories – causes obesity that then causes diabetes and heart disease. Instead he brilliantly summarizes the evidence that sugar – fructose in table sugar, in fact – alters metabolism so as to cause insulin resistance and obesity together. Recently, in a far more plodding and regrettably long article I parsed through what I consider the most important evidence for what Taubes discusses: Recent trial work comparing fructose to glucose that shows … Continued
Multiple articles on this site point toward better health from reducing intakes of sodium and refined sugar. They are well referenced and well supported by scientific data. Recently Consumer Reports, an outstanding purveyor of unbiased information to US consumers has summarized contemporary scientific opinion in a more fluent and convincing way than I or Jill Harris could achieve. Their recommendations align with ours concerning sugar, and sodium. Likewise, they offer, as we do, tips on how to read often misleading package labels. Being a popular magazine they do not consider bone effects of sodium, as we do, nor – of course – our unique issues about kidney stones. Even so, they have put their weight and reputation on the scale … Continued
Glomerular filtration is the main life sustaining kidney function, and kidney stones can cause enough damage to lower it. Usually the reduction is very modest, but sometimes stones can cause kidney failure. This means, like all diseases, stones are best prevented as early and as completely as possible. This ‘just the facts’ version tells about what filtration is, how physicians measure it, how much kidney stones lower it, and how often that occurs. Two longer articles give the details. One is comprehensive. The other focuses on only kidney disease, but is long. Much of this text is redacted from the other two articles. I left out pictures, data, and links to PubMed to emphasize the main points. The featured painting is … Continued
The first article in this series of three summarizes the importance of filtration, the rudiments of how we measure it, and the results of research concerning how kidney stones reduce it. This article gives the details of kidney function in stone formers. It carries the key references, and supports the summary assertions of the much shorter precis. But because it does not duplicate the brief introduction to filtration per se, I advise reading the shorter first article as an introduction. The third article tells how filtration works, and the details of its measurement in patients including the eGFR estimating equations. It illustrates how filtration affects key stone risk factors and offers a brief tour through the kidney for those who … Continued
Kidney stones form at the tips of the renal papilla, and what forms them is the functions of the kidneys as driven by the needs of systemic homeostasis – maintenance of constant and normal blood levels despite wide variations in intakes. Stones themselves, obstruction from their passage, and consequences of infection and surgery all can damage kidneys. Multiple studies have linked stone forming with kidney disease, usually mild but sometimes serious. Kidney disease is detected mainly by tests of glomerular filtration. Even more, the very formation of stones depends in a way on the high filtration and subsequent reabsorption of critical materials like calcium. Given this anyone with kidney stones needs to know what filtration is, how physicians measure it, … Continued
Who doesn’t love dessert? I, for one, thoroughly enjoy cookies, cake, and ice cream, but I keep it for here and there and not everywhere. I know that many of you love it, too, because you tell me everyday that this is the hardest thing for you to avoid. But I am here to tell you that it is possible to lessen your sugar and still want to wake up in the morning. Really. I work with many clients who have a very tough time lessening their sugar intake. It is hard at first, but it gets better over time. It’s Important To Reduce Sugar Another recent article makes the case. Added, or refined sugar (sucrose) can raise your risk … Continued
This is our main article on Randall’s plaque, a papillary nidus that fosters growth of calcium stones. Other articles on this site illustrate plaque, and discuss plaque as a mechanism of calcium kidney stone production. But these have used plaque as part of explanations for stones not as something in itself. This article provides a full narrative about modern plaque research. Because our own research group performed much of the modern work we may seem perhaps partisan. But in fairness we do show what others have contributed. A word about context. From long before our time to now, scientists have recognized the massive numerical predominance of idiopathic calcium oxalate stone disease as contrasted with stones arising from systemic disease. Our concern here … Continued
We love it. As a people Americans eat 66 pounds of added sugar a year per person. Each one of us eat that much added sugar. Yes, that much table sugar, sucrose, the bad stuff. It may be bad but I love it, passionately, and with the fondness only time can add to a relationship. Frankly, only the writing of this site put me on to the dangers of excess added sugar. A physician all of my adult years yet blithe enough about added sugar I knew its main drawback as mere obesity. Now I know better and plan to leave it be and live my life without its company. The pretty graph at the right comes from the US … Continued
My book chapter makes the prime point that low urine pH causes uric acid to crystallize in urine and produce kidney stones. But it does not detail what lowers urine pH to such an extreme. In part, bowel diseases lower urine pH. That is another subject altogether, because they also cause calcium stones. So they need their own articles. But in the main, low pH arises in people who are obese, have metabolic syndrome, diabetes, vascular disease all in some combinations. As an alternative,sometimes low pH associates with gout and none of these are present. In either case, this article concerns what kidneys do to lower pH in the absence of an obvious systemic cause. This article parses out and pulls … Continued
Watch the Video In my very long and complicated article I detailed primary hyperparathyroidism (PHPT) like a good scientist should. With all my heart I tried to make it plain enough for people in general to get a sense of how things work, but looking back on it, I doubt many will. Anyway, this book structure makes a place for summary and synthesis. Is this PHPT lite? Not really. It is PHPT practical, devoid of all but assets material to evaluation and treatment. Even so, in those areas I go into perhaps greater depth than in the parent article. The two articles complement each other as best I can arrange. Alabama Grist Mill Dam by Beverly Hammond catches the sense of how … Continued
Primary hyperparathyroidism (PHPT) is a systemic disease caused by an excess of parathyroid hormone secretion. It causes calcium kidney stones but also multiple other abnormalities, especially of bone. Here, I am concerned with that subset of PHPT patients with kidney stones. A Curable Cause of Kidney Stones Unlike most stone formers those with PHPT have a good chance at permanent cure. This makes detection of PHPT a paramount aim for patients and their physicians. As I shall tell you, PHPT raises serum calcium above normal and is detected from blood test results. The elevation of serum calcium can be slight and variable so patience and persistence matter a lot. Once diagnosed, PHPT can be cured by a surgery that modern … Continued
This is a story about how well the supersaturations we measure in 24 hour urines reflect the average supersaturation in the kidneys of patients, whether supersaturations match kidney stones – match the crystals stone contain. If they do match well, we can trust supersaturations as our guide to treatment. If stones and supersaturations do not match well, what value can supersaturation measurements have? They could mean nothing. Stones form over months or even years. Can a few frames tell us about a movie? It is also a story about my own past because Joan Parks and I did the work over 20 years ago. Though old, human observational data do not go out of date. The stones and 24 hour urines from those patients … Continued
Our newest venture – the Kidney Stone Prevention Course. It arose from this idea: Kidney stone prevention depends a lot on proper diet and fluids, which patients control. This site tells people what that diet and what those fluids should be, but not how to eat that diet or drink those fluids in real life. They have to learn how. So we built the kidney stone prevention course to help them learn. Just as Raphael imagined generations of brilliant minds come alive together in The School of Athens (Raphael, 1509 -1511; Apostolic Palace in the Vatican.), we – on a vastly lower plane of existence – imagined and have, in the kidney stone prevention course actuated the knowledge on this site into real life. … Continued
Do you need a low oxalate diet? Who does? Who does not? How can you tell? I chose the gorgeous painting by Raphael that hangs in the Musée Condé Chantilly because three surpasses one. VIDEO FOR THE ARTICLE Who Needs Low Oxalate Diet? Most of all, those whose stones contain calcium oxalate crystals and urine oxalate enough to promote such stones. Less so those with systemic diseases – bowel disease, malabsorption syndrome, bariatric surgery, and primary hyperoxaluria – that raise urine oxalate. Their diseases require many treatments, only one of them low oxalate diet. Therefore, I write here for only patients without a systemic cause of stones. Do Your Stones Contain Calcium Oxalate? If your stones contain little or no calcium oxalate crystals, and urine oxalate itself poses no danger to … Continued
The old fashioned intravenous pyelogram pictured in the header of this article depicts the normal left kidney of an 18 year old woman, and her severely obstructed right kidney – from a stone. That kidney has lost some of its tissue. In his review of stone pain, Mike Borofsky showed that obstructing the kidney of an animal reduces its function and provokes inflammation. Obstructing stones affect human kidneys similarly, and can damage them, but we know fewer details. Fortunately, kidneys seem resilient enough that most stone formers maintain reasonable kidney function. But stone formation not rarely leads to kidney disease. Though often mild, in some cases losses can be severe, even to kidney failure. What do we know about the … Continued
Would anyone bet against water to prevent stones? Here is the first of new articles that highlight stone treatments in a simple format. These new articles were provoked by what patients asked for, and by Freakonomics. Because patients asked for clear answers about treatments, I lifted ‘water’ out of my long article on treatment of calcium stone formers, and simplified the style so the main points stand out. I also suggest betting, something we all understand. Freakonomics offers a three part podcast about the woeful state of medicine. Doctors, they say, rely on received wisdom, poor clinical trial design, and bad data. At the end I ask you to vote if we kidney stone physicians suffer from these three defects, and by how much. Voting sharpens the mind, or should. … Continued
My Question Tell me what you want next on this site; that is my question. I have been writing this site – with the able help of my co-authors – since July 2014, and have reached what I might call a kind of plateau. Much of what I came to say about the most common kinds of kidney stone patients is said. Because the main work is done for the moment I have come with my question to you. The readership of the site has grown from 50 people in the first month to a present running average of 55,000 – 65,000 people monthly, depending on the season, and many of the visitors read quite a bit each. People find the site valuable, … Continued
It was a comment by Dr. Robert Perlman, a friend and brilliant scientist in the field of evolutionary medicine, that set me off on what I can only call a historical and scientific pilgrimage, a pilgrimage to the beginnings of the modern guidelines. At the end of my most recent article on the guidelines and our present stone fomenting diet, he pointed out that the US diet guidelines are so influential and the new ones so helpful in management of kidney stone disease we all must question who creates them, and how. The guidelines must have, he implies, the kind of elaborate and winding history one expects from a succession of governmental committees which, howsoever well served by volunteer scientific experts, can be subverted – by money, by … Continued
I have summarized the scientific evidence that low intakes of diet calcium and potassium and high intakes of refined sugar and sodium and protein raise risk of stones and loss of bone mineral. I have pointed out that the recommended US diet specifically seeks to correct all five of these risks and we should recommend it to all of our stone patients unless contraindicated by some specific problem. But I have not as yet shown to what extent we as a nation eat a diet deficient in calcium and potassium and excessive in refined sugar, sodium, and protein. In other words I have not as yet quantified the extent of the problem that stone forming patients face. Here is evidence from a large body … Continued
A Remarkable Concordance From 1980 to now the US government has published diet recommendations for the American people. Gradually and over time these have become quantitative and specify amounts of critical nutrients such as calcium, sodium, refined sugar, protein, and potassium – as alkaline anions in mainly fruits and vegetables. The goals are reduction of osteoporosis, hypertension, obesity, and diabetes. I shall call this the Ideal US Diet. Surprisingly, though aimed at stone prevention and management of bone disease from idiopathic hypercalciuria, decades of kidney stone research have identified precisely the same diet. Even more surprising, the Diet Against Systolic Hypertension (DASH) diet resembles the current Recommended US Diet, and stone researchers have found a reduced risk of stone disease in people who eat ‘DASH – … Continued
Medullary sponge kidney (MSK) is more spoken about than witnessed, and more witnessed than accurately diagnosed. This patient adds to the 12 we have described in our publication, and adds also in having a very long and evolving history with one of us (FLC). We write for a general audience yet hope to include a level of detail that satisfies physicians and scientists. Here, we may fail of clarity to the one audience or of a sufficiency to the other because the disease is complex. But withal, the evolution of diagnosis and care for this person so educates and the surgical anatomy and histopathology so instructs we have chosen to share the experience. What is it we are sharing? MSK is a Unique Disease MSK is remarkably specific in … Continued
I thought it was time to sum things up, to offer an utterly practical guide to stone prevention. So here it is. You have kidney stones, even one, what next? There are things you need to have your physicians do for you. There are things you need to do for yourself. Then, there are things that may not need physicians but other kinds of support. To unclutter the text I listed the key links at the end of the article. WHAT YOUR PHYSICIANS NEED TO DO Stones can come from systemic diseases, and only a physician can determine if that is the case for you. A not uncommon example is primary hyperparathyroidism that is curable but with surgery. There is a … Continued
Recently we presented what we think of as The kidney stone diet, meaning a unitary diet platform suitable for idiopathic calcium stone formers in otherwise good health. The story of that diet and the implications it has for stone prevention deserve perhaps a bit more commentary than we allowed for in the original article. The lovely image – Hendrick van Cleef, The Building of the Tower of Babel hangs in the Kröller-Müller Museum. He (1525 – 1589) is one of a family of famous painters and much admired for his brilliant textures and colors. Babel was to keep us aware we are divine. The Narrow Winding Path Over many decades, kidney stone researchers have gradually recognized what the ideal kidney stone diet might be. They did … Continued
If we put together everything on this site about diet for kidney stone prevention we get a reasonable and consistent image of one basic pattern. It is more or less what is ideal for idiopathic hypercalciuria and for reducing urine oxalate. It is the diet that has been used in the one major trial of diet for stone prevention. It accords with modern recommendations for the health of the American people. More or less, after all is said, there is only one diet plan that meets the needs for kidney stone prevention and we have called it ‘The Kidney Stone Diet.’ Of course, we are speaking of the diet for treatment of idiopathic calcium stones. Stones from systemic diseases, like bowel disease, primary … Continued
Some of us overdo things with shakes and powders, some with 2 pound steaks. Others love sweets too much and don’t eat much protein. Like all the diet factors in stone and bone disease, protein intake is complex. Certainly, we all need protein in our diet but how much? Experts debate the best course, and patients wonder what to do. Abraham van Beijeren was, by the way, little recognized in his day but now considered a major painter of ‘luxuries’ like this standing roast. I chose it, as opposed to others more brilliant, because it looks modern – I have seen something like it on my own dining room table. In preparing this article I have made considerable use of the analyses performed by professor … Continued
Here are all the trials for prevention of idiopathic calcium stones, and my personal approach to using their results in clinical stone prevention. The whole site thus far has been built to support this article, which is the capstone of the enterprise. To highlight its importance I have made it header type larger.
Beside the usual references, I provide spreadsheets that contain all of the trial stone data with links to the original articles and PDF images of the articles. I also provide spreadsheets of stone risk data from the trials that I use in my analysis of the physiological responses to treatment. So this is a definitive as I can make it. I have left the two preceding videos in red because they are the steps up to this article, and perhaps people might want to view them in preparation. The two prior articles on phenotypes that come before the videos are also preparatory to this final presentation.
I say final because with the full presentation of all of the trials we have more or less covered the entirety of idiopathic calcium stone disease and need to move on to other stone types and to the systemic diseases that cause stones.
With considerable trepidation, I unfurl my first and certainly very unpolished video offering. The good part of the articles on this site is their devotion to scientific accuracy and referencing from PubMed. The bad parts are their opacity, length, and difficulty. I have long been a public lecturer and decided that video offerings might be a valuable add on. There is more room, I think I speak better than I write, and it seems to me one video can summarize and complement a group of written articles, so I did this one. It covers crystal formation, how crystals are made, and where in the niches and crevasses of the kidney they actually form. Its message is my usual one: Prevent crystals and you prevent stone disease. This is a beta version. I know it has some errors in it. I also know it lacks refinements I need. But, refinements and corrections will come. Let me know.
Here is the most common kind of stone former, described in such detail as one can muster up at this time. They are simple to diagnose: Stones containing a preponderance of calcium oxalate, no uric acid, struvite, cystine, brushite, drugs, or rare organic materials, and exclusion of any systemic disease as a cause of stones. More or less, these patients are stone disease as it is seen in primary care and most urology practices. Of the millions of stone formers most are like this. The trials for prevention of calcium stones have mainly used these patients as a majority of subjects. However common they may be, and easy to define, they are complex in the way that they make stones, and it appears that there may be not one but perhaps two kinds of idiopathic calcium oxalate stone former. Because of modern flexible ureteroscopy the types of idiopathic calcium oxalate stone former will soon be told apart during stone removal surgery, and patients and their physicians confronted with a variety they may not fully expect. This article sums up what is known, as best as I can manage.
The second in this series of stone forming phenotypes, the calcium phosphate stone formers are less numerous than the calcium oxalate stone formers, but perhaps more worrisome, and certainly more complex. There are two types, those whose stones contain any brushite – an unusual form of calcium phosphate in stones, and those whose phosphate is only hydroxyapatite – the mineral found in bones. This latter group is to a large extent composed of young women, for reasons we do not know. Phosphate stones are likely than the calcium oxalate variety to be numerous, and often produce nephrocalcinosis, a mixture of small stones and tissue calcium deposits. Nephrocalcinosis, in turn, is often labelled medullary sponge kidney simply on radiological grounds, even when the distinctive lesions of MSK are not necessarily present. Likewise, phosphate stone patients can appear to have renal tubular acidosis because of nephrocalcinosis and because RTA and phosphate stone patients both produce a more alkaline urine than do normals, or patients with calcium oxalate stones. All in all, this is a complex form of calcium stones, challenging for clinicians and often very trying and concerning for patients with it. The article is long and difficult, so you might want to watch this video by way of an introduction.
As I see things, all of stone disease concerns the balance between the opposing forces of supersaturation and kinetic retardation of crystallization. The former is better understood and more tractable because easily measured and commercially produced for clinical care. The latter is not fully understood in term of the molecules responsible and not commercially available as a clinical test. So of the two primary forces that control whether crystals can form, we have only supersaturation to use. Being so central, this one measurement, for each of the stone crystals, has unusual importance. These three relatively short videos cover the main elements of supersaturation: What it is, how kidneys produce it, and how it is measured and used in stone prevention. They combine with ‘How Stones Form’ to make what I think is a fine story about stone disease and a fine basis for understanding how stones are best prevented. I have gathered together in the article links to all of the supersaturation articles on the site thus far.
Many patients assume that they are forming calcium stones and should therefore limit their calcium intake. That assumption could not be more wrong. Low calcium diet won’t stop your stones and may even increase your risk. Lets not forget that our bones are in desperate need of calcium to avoid osteopenia and osteoporosis. But, many of the best foods for calcium are also high in sodium, and sodium raises urine calcium loss and stone risk. Now what? How Much Calcium do We Need? The National Institutes of Health tells us age matters. Nineteen to fifty year old male or female need 1,000 mg of calcium a day. Fifty one to seventy year olds need 1,000 mg for males and 1,200 … Continued
This is an article that can be written only by the readers of this site. We are not product testers nor do we do market surveys. But given how many fluid and diet apps one can find on the web and also given how many people come to this site every month we should be able to get a good idea about which ones seem of value. The benefit of accumulating your experience in comments to this very brief article accrues to all of you who come here. Whether you use an app or not crowd sourcing of a kind can tell us all which ones seem really good, and we can all use that knowledge. There are almost no words in the article, but as the results come in – in other words if you will share – we will count up by app in a table or so, ongoing. As for smart bottles, there are only a few on the market, but we should be able to get an idea about them if you will share. So, here it is: A blank slate for everyone to write on so everyone can benefit. Please share.
This little goodie started with my partner Dr Anna Zisman who to wanted us to have a simpler format for patients to follow in looking at their 24 hour urine lab reports. Answer five easy questions and get back a list of what you have to do with fluids and diet. Try it. Let me know if it works. If not, can you help make it better?
Well, here it is, the last pillar in the foundation. My goal is to enable patients to achieve successful stone prevention and I believe this requires a partnership with their physicians, a partnership in which they play a very active individual role. Patients after all are the ones who can manage diet, fluid intake, and life demands, only they can assure that 24 hour urine collections are representative of normal life, and, frankly, only they can decide on a life of long term prevention. Stones being rarely fatal and usually not a cause of progressive kidney disease, patients can elect prevention or not, and their physicians are in a role more like attorneys and accountants than authoritarian directors of events. But as in Eden, one can expect proper choices only if one has provided full knowledge, which I have set out to accomplish. By proper I mean most suitable to patients given full knowledge, for some may not care to exercise themselves so much as I think they must to be successful, whereas others may consider the work of prevention slight indeed compared to the consequences of continued stones. In any event, this article is the end of that cycle of enablement I can manage, and I put it here, as in all writings, as the chef puts out her best effort – to face the indifferent judgement of the gourmet.
Dr. Mike Borofsky authored a favorite article on this site – Pain from Kidney Stones. Now, he has authored our first article on stone urology, meaning the urological surgeries used for treatment of stones in the kidneys and urinary tract. Ureteroscopy is fast becoming the preferred approach, outstripping shock wave lithotripsy and percutaneous lithotripsy. This is because the instruments for ureteroscopy offer superior optics and are flexible and small enough to get from the urethra up into the kidneys and into all of the crevices of the kidneys where stones form and lodge. Armed with tiny but powerful laser fibers, the new ureteroscopes permit surgeons to fracture stones in the kidneys and turn them into mostly harmless dust that passes silently for days or weeks thereafter, or into small fragments they take out during the procedure leaving not a speck behind. It is a brilliant time to be a young urologist and use these marvelous instruments to do what would otherwise require a far more complex and risky procedure (percutaneous nephrolithotomy) or depend upon an indirect and often incompletely effective one (shock wave lithotripsy).
These two articles cover the main stone types, and this new one on uric acid parallels the prior one on calcium stones. Like the calcium stone article it is meant for patients, although physicians might like some of the nuances. The purpose is not to make patients into their own physicians but to enable them to understand their own stone forming abnormalities. My ruling hypothesis is that patients want prevention, and will embrace and implement the changes needed with more enthusiasm and endurance if they fully understand the goals. LIkewise if they can themselves follow the effects of their efforts on stone risk factors they will believe that what they are doing has real meaning. I know that hypotheses are for disproving, and I know someone may well do a prospective double blind randomized trial, some day, to test mine. Right now, I believe in the idea because of Eden whose resident twosome were not just told about the tree but exactly why they should not eat of its fruit. I know it is an unfortunate comparison, given the outcome, but much effort was expended on education. My source for the details, apart from the Hebrew Bible, is Milton, J: Paradise Lost; Books V – Viii.
This site is meant to promote prevention and my current hypothesis is that enabling patients to read their own 24 hour urine tests with a professional eye will help achieve that aim. It is not an easy task. Lab reports, even the best of them, are dazzling arrays of numbers in often mysterious units. Even physicians have some work to do. But numbers are numbers and people can read them if they have the code. Here I have parsed out the main numbers for the calcium stones: Volume, calcium, oxalate, sodium, citrate and pH. Because this is the first article on reading this kind of report I also discuss collection quality, conversion of units – some labs report, as an example, calcium in mg/24 hour, others in mmol/24 hour, even mEq. So I introduce the simple conversions needed to use what I have written for a report with different units. Likewise I introduce how urine creatinine can be used to estimate collection quality. The supersaturation come at the end, as they should, being the final summary of everything. The tone is about that for trainees in nephrology or urology I have often worked with but with jargon elided and a focus on lab results per se. Those interested can follow the links into the thickets of the site which hold enough to satisfy most appetites. The main purpose is to enable patients to cast a cold eye on their own problems and on the results of treatment efforts so that in the event saturations can be effectively reduced and stone recurrence with them.
The thiazide type diuretics are able to reduce new stone formation and are an important part of stone prevention regimens. Here is all about these drugs: The trials that show they work; How they work; What they do for bone: Certain precautions in their use. To give a pill to someone is to throw a seed on unprepared ground – it is a sterile and doomed enterprise. All the features of prevention from diet and fluids and lifestyle come first, so that what one can do with them is being done. Then the drug will be most useful. And, you will know by the fall in urine supersaturation achieved. Whatever it was when stones were forming is too high, and real treatment means it has been reduced. After all that can be done without thiazide has been done, there will no doubt be residual supersaturation lowering needed, or one would not use the drug. The marginal benefit of the pill can be assessed by the extra fall in supersaturation it produces. Which supersaturations? Those related to crystals in the stones forming.
Five Steps to Stone Prevention
Ultimately we want to prevent kidney stones. Trial data, and my own large experience correspond in this one point: Prevention is a reasonable objective that can be successfully accomplished. Here is my own approach, simplified into five steps. They correspond to the overarching theme of this entire site: Stones require crystals; crystals follow the laws of physics; the force that drives crystallization is supersaturation; commercial vendors in the US provide supersaturation measurements in 24 hour urines at a reasonable price. So the steps are indeed simple: Know the stone crystals; measure the urine supersaturations; lower those urine supersaturations for the crystals in the stones being formed; keep them low. If stones persist, lower them more. It takes physicians to initiate this process, and there are complications such as the occasional systemic diseases which must be detected and treated in special ways. But it takes motivated patients to carry out the long term changes in fluids, diet, lifestyle needed, and to take the medications provided. It is time to focus here: Prevention is better than surgery. To help, I wrote a companion article several months ago about how to organize your medical stone prevention visits so as to get the most out of them.
As part of a series, Jill offers this long and critical article on restricting diet oxalate. The problem is very complicated because oxalate is in a lot of plant foods and these are foods we need and often like. Using the Harvard oxalate list with cross referencing with another list from an excellent academic institution, Jill finds her way between the problems of too much oxalate and too little to eat. She offers a whole day meal plan outline people can fill in with their own preferences. Some key scientific papers are reviewed at the end to show the basis for her advice.
Jill Harris offers another of her amazingly useful and popular articles, this one on the how of low sodium diets. As she has done for fluids, Jill takes you into her own kitchen and dining room and shows you how to limit salt intake and yet fully enjoy your meals. She has had years of experience coaching patients about exactly this kind of crucial life management, and it shows. Her articles are the most popular on this site, and this one is destined to join her others in helping thousands of people actually do what their physicians ask them to do: Eat less salt to stop making stones.
Two good trials support lower sodium diets as a way of reducing new calcium stone formation and of protecting bones from calcium loss. The physiology behind these trials is detailed in the articles on idiopathic hypercalciuria and salt. In Italy at least, and in men with calcium stones and idiopathic hypercalciuria, a diet low in sodium, moderate in protein, and high in calcium leads to less stones than low calcium diet alone, and in fact to a rather low new stone recurrence rate. Among postmenopausal women, a high calcium low sodium diet brings bone mineral balance into the positive range: Bones add mineral. Neither trial is comprehensive in covering men and women, young and old, US vs. Italian cuisine, but they are the only ones we have of this quality, they are consistent with the science we have, and convincing. To me they are enough to recommend low sodium diet, moderation of diet protein, and high diet calcium for calcium stone formers with idiopathic hypercalciuria, recommend this kind of diet without reservation pending what I hope will be more trials which cover a wider range of patients and of ages. It is this kind of additional trial we really need in the US right now, substantial, bearing on really important diet interventions, and arising out of a sound scientific base.
It has always seemed to me that medical practice is a dance. One leads, perhaps, but the other does, too. If physicians know more steps, patients can prepare their parts in advance and organize their large roles in long term treatments so the final result is graceful and ultimately elegant in obtaining the best results with the least extra effort and resources. After all, it is patients who know the past and will determine the future. Here are lists for you, ways to think about time with physicians, and especially a way to think about your treatment over the long years of stone prevention. For it is years, this being a chronic and recurrent disease, years of work by you with only a rare burst of medical guidance here and there. Yet so important as rare needs preparation and curating so what transpires is not lost. What is here is my own ideal of how things should happen, how the dance is conducted – so brief, so important.
Idiopathic hypercalciuria may well be the most complex and important issue in all of medical management of calcium kidney stones. It arises within the elaborate systems that regulate calcium metabolism and produces both a risk of stone formation and of bone disease with fractures. IH is strongly familial, almost certainly genetic in origin, and present in children as well as adults. Treatments used include high calcium – moderate protein – reduced sodium diet, moderation of dietary sugar loads, and potassium citrate, and thiazide type diuretics, each of which act through different and reasonably well characterized pathways which cannot be understood without a knowledge of how IH works in the first place. Unlike stones themselves, supersaturation, or citrate, each a very large and important topic, IH cannot be presented well – at least by me – in separated linked articles but only in one article that carries its many intersecting physiologies along side by side and uninterrupted. Being a long and comprehensive article, foundational for this site and – to me at least – for comprehension of the whole topic of pathogenesis and treatment of nephrolithiasis, this article is not necessarily meant to be read all at once but rather used as a resource. I will cover the treatments of IH later on, in separate articles.
This is a foundational article for the site. High rates of urine calcium excretion (hypercalciuria) will raise calcium concentration at any given urine flow rate, and therefore raise supersaturation with the calcium stone forming salts. Genetic (‘idiopathic’) hypercalciuria, simply the upper end of the normal range, is greatly over-represented among stone formers, and idiopathic hypercalciuria (IH) is a main focus of treatment for stone prevention. As well, people with IH, stone formers or not, are at risk for bone disease. This article introduces hypercalciuria: IH itself and a few of the less uncommon named diseases that cause hypercalciuria like primary hyperparathyroidism, renal tubular acidosis, and sarcoidosis. It mentions confusing disorders such as normocalcemic primary hyperparathyroidism, secondary hyperparathyroidism, and familial hypocalciuric hypercalcemia. It also offers evidence linking specific levels of urine calcium excretion to risk of stones, a very important matter in deciding what needs to be treated.
Being so important, the very force that drives crystal and stone formation, supersaturation has enjoyed considerable attention on this site and it seemed time to gather the articles about it into a coherent narrative. The walking tour seems apropos as such tours visit a group of related sites and have, or should have, a guide to put each one into perspective and extract from the entire group some large and generous idea about the world from which they arose. My prior one on stones themselves attempted the same.
Given that kidneys supersaturate the urine by conserving water, no treatment can be more immediate and direct than to drink more water than one needs so the kidneys can excrete it and in the process dilute the urine salts – which is to lower supersaturation. Alas, there are many patients who cannot or will not drink enough water, and it is these Joan Parks writes about in this article. Over our 40 years of collaboration very many patients with the problem of persistent low flow have come through our stone program at UC, but Joan and I never wrote a paper about them so much of what we found is buried in their charts. By way of redress, Joan has conjured up a lot of details that we think people will find valuable, even though they have not been shaped into the formal character of a scientific paper.
Not a few of you have heard this word and wondered what it meant for your health and management. Here is what it means. On the one hand, crystal deposits in kidney tissue. On the other, the name radiologists use when they see calcified regions overlying your kidneys, regions that are not clearly free stones but could be stones or tissue mineral. They really cannot tell with great precision. They never could. Modern high resolution ureteroscopy can tell, and surgeons everywhere have adopted this wonderful technology into common practice. You need to know this. Those of you who carry the diagnosis of nephrocalcinosis will all benefit from modern surgical visualization as opposed to indirect means of radiology.
If you want a comprehensive view of what kidney stones are and how they are made, I have put together various of the articles in this by now rather large site to make up a kind of story, or narrative, or, as I like to think of it, a walking tour. Read in the order I suggest, and take a look at the few narrator comments and I promise a nice overview of the topic. More will come if people seem to like this format.
Many people have multiple calcification in their kidneys and urinary tracts which show up on CT scans and are labelled ‘nephrocalcinosis’. When they look like multiple small calcifications massed together radiologists often label the disorder as MSK. Old fashioned x-rays with contrast agents were actually more discriminating for the diagnosis but have passed into disuse. Contrast CT can also help make the diagnosis but is rarely used to diagnose stones. Modern high resolution endoscopy has, fortunately, taken over as the main new way to manage stones and with such instruments surgeons can confidently diagnose MSK. Because new, the change in the way we diagnose MSK will inevitably change what people are told is the cause of their stones. MSK has special features which complicate treatment. A large majority of people presently labelled as having MSK probably do not have it but rather have one or another more common stone forming disease. The message is simple: We need to separate out who has what and provide exacting and reliable treatment using the most modern techniques.
Dr Michael Borofsky is a young and brilliant surgeon specially trained in kidney stone management who offers us the article any patient or family member or friend will want to devour. Stone pain is awful and arises from complex abnormalities that are important to know about. He makes clear how much inflammation occurs, why a lessening of pain might not signal betterment of obstruction but only a fall in blood flow to the kidney. Most importantly he writes about the possibility that stones which do not obstruct might still cause enough pain to disable people, interfere with life, and lead to drug dependence. This controversial area of kidney stone surgery requires new studies, but before they are done patients and physicians need to know about the possibility that chronic pain in a stone former may be coming from an innocent appearing stone we have up till now dismissed.
So many times I have been misled and my patients also because of misunderstandings about what 24 hour urine collections can tell us. They are single frames out of a movie that runs lifelong so it is imperative people collect as they were when they made stones or as they are pursuing their stone prevention treatments. The concept is easy and easy to ignore, put aside, forget about. Jill’s offering is not only useful for the first time collector, but every time – as a reminder.
Dr. David Goldfarb has taken on the American College of Physicians concerning the flawed guidelines they have promulgated for prevention of kidney stones. I have criticised these guidelines – for fluids and medication use – in two prior articles. My criticisms were about their intellectual failings and naivete concerning medical practice. His are broader because in addition to their intellectual and medical flaws they were published against the advice he gave as a peer reviewer of the articles. Furthermore, as he points out, they do not properly acknowledge the guidelines of the American Urological Association, which represents the main body of physicians who actually take care of stone patients. The AUA guidelines contradict those of the ACP and, in my opinion, and his, properly so. This matters to you as patients. If your doctor has been told something is good and proper, by physicians promoted as experts by the ACP, he or she may act accordingly, and that may not be good for your care. Read what Dr. Goldfarb says, and likewise what I have said about this matter.
Get ready. We have covered stones, supersaturation, stone risk, potassium citrate, and more, but now we are coming to a central mystery – a pivotal issue in whether or not treatment will work or not. Calcium is the first name of most kidney stones, and the calcium in stones comes mainly from the urine. So the urine calcium is a big deal. Yet it is sodium chloride, humble table salt, that strongly controls how much calcium is in the urine. Genes play a role, protein, too, lots of factors. But salt intake is so modifiable, so amenable to change it has a massive role in treatment. Here is my best on the subject. I hope you like it.
This is the essential basis for modern kidney stone prevention. I review its limitations, and how much information it provides on the pattern of stone risk factors for a given patient. Also, I show how much variation within a day hides in the 24 hour averaging and what you should do about it, and point out why you need at least two 24 hour urines before treatment. If you have signed up for my emails, read the one for this article because it explains how it is put together and best read.
A very useful introduction by Dr Anna Zisman. In general the articles on this site are a bit more detailed and referenced than this one, but the disease is very complex and we thought a fairly simple and brief introduction would be ideal for patients and their families.
Obesity Is Epidemic World Wide Anyone can find ample evidence of US obesity. Here is a recent CDC map. In response, ‘bariatric’ surgeries designed to reduce body fat stores by limiting and re-routing nutrient absorption have risen to very high levels. The American Society for Metabolic and Bariatric Surgery estimates rates at 158,000 procedures in 2011 and 216,000 in 2016. Europe, and the rest of the world share the obesity problem. This is one of an almost endless number of graphs and maps I can put forward to document what is in fact a remarkable event in human history. Naturally, bariatric surgery rates have risen world wide, as they have in the US. The magnificent Tower of Babel Pieter Brueghel the Elder (1526/1530–1569) hangs in the Kunsthistorisches Museum, … Continued
This article will take you for a ride and offer you some surprises.
It is about how urine resists crystallization, a property summed up in the forbidding term ‘Upper Limit of Metastability.’
But don’t be scared off.
The ULM is a powerful concept that will help you understand the real issues in stone prevention.
And, at the end of the article, you will find that quite possibly it is not the mysterious and giant collection of urine proteins which protect us against crystals but perhaps our familiar citrate molecule in league with another small molecule, inorganic pyrophosphate which is a close relative of the bone sparing and common bisphosphonate drugs.
This article is long and complex but I think patients will want to trouble themselves to read it. It tells the story of how our diet in the US, Europe, and urban Asia imposes an acid load which the kidneys must remove. That demand forces them to conserve citrate which is a natural defense against kidney stones. The pills neutralize the diet acid, and release the kidneys from their lifelong task of compensating for how we eat. That is why the urine citrate can rise. Removing acid is a major task that affects how kidney cells work. The humble potassium citrate pills have massive and probably beneficial effects on those cells. Of course, diet could the same as the pills, but how can one pursue a diet against the tendencies of the culture? Even with a will, most of us could not get it right – the balance of food, a proper nutrition. I could not advise we try.
Here is part two: citrate slows and can even stop stone crystals from growing. It does this by binding calcium, not the calcium in the urine but calcium atoms already part of a calcium stone crystal.
By binding to structural calcium atoms, citrate interferes with the orderly arrangement of atoms that is necessary for the crystal to exist, so one can think of inhibition and binding as two aspects of one power.
Like binding itself, this is not easy material to present or read. It is like climbing a tall hill for the view. If you will follow me up, I promise a reward.
The citrate molecule in urine is thought to protect against formation of calcium stones. This thought began as reasoning from chemistry, and culminated in clinical trials which substantiate the idea. As a result manufacturers produce citrate products for medicinal use, and doctors prescribe the medicine. All this is a wonderful success story, a kind of perfection of the paradigm of translational science: From science to a treatment for patients that reduces illness from kidney stone disease. But what, exactly, is the science? Can scientists not enjoy the story of such a success, physicians derive from it a deeper understanding of the drug they so regularly dispense and patients the comfort that a perfected knowledge support the rightness of their prescribed treatment? Citrate The Molecule As … Continued
Potassium citrate, thiazide diuretic agents, and allopurinol are the three medications that have a proven ability to reduce kidney stone formation.
Because fluids are so valuable and safe, we have emphasized their use as a basic treatment for all forms of stone disease. Here, I present the evidence that potassium citrate adds protection. The evidence is in the form of 5 trials that appear well done.
Some of the background for this article was already prevented in our discussion of the costs of this drug. Likewise, that discussion presented alternative sources of alkali that should more or less mimic the protective effects of the drug despite lack of direct trial data. I say this because the drug is a simple alkaline salt.
The article is written for anyone. Physicians will fill in more blanks than patients, but patients can easily analyse the numbers.
This post concerns guidelines just released by the American College of Physicians (ACP) concerning prevention of calcium kidney stones. In the article two specific guidelines are proposed. The first, on fluid management, is covered in another post. Here I discuss their views concerning uses of medication. The discussion here is in advance of what is already on the site. Whereas I and others have put up more than a few articles about fluids, the issue of medications has not arisen. This is because medications have always been used to alter excretion rates of three atoms or molecules in urine thought to alter risk of calcium kidney stones: calcium, citrate, and uric acid. I have not as yet set the foundation for discussion of … Continued
The American College of Physicians has published its Clinical Guidelines on dietary and pharmacological management of kidney stones in adults. My purposes are to place the results of their deliberations in clinical context and also draw some conclusions about research we might want to perform. Though only two in number, their recommendations cover virtually our entire field of practice. For this reason I thought it best to consider each of the two separately, in different posts. As a simplification, I accept the statistical analysis as correct. Partly I suspect it is correct. Partly, I am not engaged with the methods of the analysis so much as I am with how we view their results and their conclusions. The ACP Guidelines can be influential among primary care physicians. As people involved with … Continued
How does anyone really know the amount of fluids you need for stone prevention? Dr. Elaine Worcester and I have put together much of what is known about the topic and offer some reasonable guidelines. Our caveat: These are guidelines, but have your physician do the final decision. Not everyone can drink large amounts of fluids, and not every patient needs the maximum amount, either.
Well and good to say, ‘Drink 3 liters of water a day to prevent kidney stones’, and go on to something else. It is another to accomplish that feat. Don’t some drinks raise stone risk – like coffee and tea? What about Coke, diet drinks, beer and wine? Is anyone supposed to make do on all water? Here is a post by Jill Harris that offers answers and even daily menus of beverages. As things turn out, there are a lot of choices, a lot of ways to get in all that fluid, every day.
I never have been a remarkable shopper, so those who know me well might wonder at a post about prices. Even so, patients have complained and wanted alternatives to potassium citrate pills which have become too costly for them. I did a bit of web shopping for retail prices, and although they vary, even the lowest seem too high for most budgets. A very brief look at insurance plans under Medicare: Some plans just pay the whole bill; some charge $10.00 for 100 pills; some charge a percentage of retail; some do not pay. So I have put together alternatives which taken in aggregate permit everyone to piece together a replacement for all or at least some fraction of these pills whose price has become just too high.
The Web abounds in lore about kidney stones, perhaps because stones are common, and perhaps because they are painful and people want remedies. This particular remedy caught the eye of Dr. Anna Zisman because one of her patients read about it, tried it, and seemed to get worse instead of better. She did some research on the matter and decided it was worth while to let patients know that the treatment is not ideal and possibly can do a modest amount of harm. Her charming and useful message is typical of her critical and thoughtful analysis of medicine, and especially this tiny but active area of stone prevention.
One might think nothing is easier than drinking water; my experience is that nothing is a lot harder, as least for a large fraction of patients. The new post by Jill Harris is all about how. Jill spent 12 years at Litholink corporation, now a subsidiary of LabCorp, supervising their team of telephone patient care representatives. Her team, and she herself, dealt with thousands of patients, and how to drink enough water was always a large issue. As practice will do, she has gradually built up her bag of tricks for patients, and shares some of them here, with you. Now in her own practice, Jill continues to help people prevent stones by showing them how to actually accomplish what their doctors urge them to do.
Something In their Papillae Video: The Story With Less Detail The papilla is where urine leaves the kidney. It is where plaque forms, and plugs. Most calcium stones form there. Though just a few millimeters long, those few millimeters extract water and supersaturate the urine – the supersaturations create stones. Take a look at how the kidney is put together, if you do not remember. Stone Former Papillae Absorb More CT Radiation than Normal On CT, the papillae of stone formers are darker gray than normal – more dense. You cannot see it, too subtle. But the routine tools on every CT reader let you measure density – how much radiation is blocked. The density is in Hounsfield units, HU, higher … Continued
Supersaturation Supersaturation names the force that makes crystals. Because it does, we measure supersaturation to understand why a patient makes stones, and we reduce risk of more stones by lowering supersaturation. Fortunately, universal and quantitative laws govern how atoms and molecules form crystals so we can calculate supersaturation and predict the risk of crystals using equations that apply everywhere, even in the kidneys and urine. Supersaturate a solution yourself, and see how it works. Supersaturate your own sugar solution Saturate Your Sugar Solution Find a heat resistant glass container, fill it with water, and stir in table sugar until no more will dissolve. You will know when no more will dissolve because extra sugar remains at the bottom even if you shake … Continued
A NEW AND USEFUL REVIEW THE FUNDAMENTAL MEASUREMENT OF STONE PROPENSITY The three Moirai, or the triumph of death, Flemish tapestry ca 1520, Victoria and Albert Museum, London, depicts Clotho, who spins the thread of life, Lachesis, who measures out the length of the thread, and Atropos, the inexorable, who cuts the thread. In book 11 of the Odyssey, Odysseus travels to the underworld where, among other matters, he learns from Tiresias his own ‘fate’; that he will return to his home and his own wife; that he will travel again to a place so far from the sea his oar will go unrecognized; and that he will die in peace, by the sea and among his own people. But he must make an offering in … Continued
The large picture shows a papillum of a patient with ileostomy as seen at surgery for stone removal. The large white patch between the arrows is plaque, the stuff calcium oxalate stones can anchor to and grow on. The yellow material between arrowheads is terminal ducts of Bellini (BD) plugged with crystals. Both are abundant in patients with ileostomy and part of how they form stones. This article relies on only three research publications, and in all modesty I must admit they arose from our research group. But in defense, one is remarkably comprehensive and one the only one with detailed study of kidney tissue obtained during stone surgery. Also in defense, their reference lists are good enough to give … Continued
Hard unwanted objects made in the kidneys, stones can cause pain, bleeding, and urinary tract obstruction. Because stone surgery often infects the urinary system, and bacteria easily infect stones retained in the kidneys, infection follow stones like a shadow. Stones surprise patients by their smallness, for all the trouble they cause, or by their largeness to think they passed through the urinary tract. But small or large, many or few, stones provoke little love. Most who form them desire no more. Yet, left to themselves, stones recur. Over half of first time stone formers form another stone within 5 – 10 years. Once recurrent, stones form – on average – every 2 – 4 years. So stone patients must pursue prevention and not imagine their … Continued
A particular manner Here and there physician friends have asked me about how I practice. But however much I have written about kidney stones, nowhere before have I told about how I practice because I feared my style might seem too odd. But it is not if you consider how narrowly I have chosen to focus. My clinical life is based on several facts. One is that doctors send me their patients and expect that I will prevent recurrent stones. That is all they want from me. This means that I can depend on other physicians to do everything else, focus on the pathogenesis of kidney stones in a particular patient and fashion for that patient a program of prevention which will … Continued
Kidney stone types Crystals make stones and their names signify the kidney stone types. Here are the names of the crystals that make the stones: CAOX, Calcium Oxalate; CAP, Calcium phosphate; UA, Uric Acid; Cystine; Struvite. The wedges on my pie chart show the relative abundances of stone types in our large population of stone forming patients. Calcium oxalate stones predominate by a wide margin in our clinic and in all others I know of. The names, matter because the whole science of stone prevention focuses upon stone crystals. Each kidney stone crystal creates its own unique illness and requires specific treatment. That is why we name stones by the names of their crystals and why when stones are analysed the results are … Continued
How bad is kidney stone analysis? I have pointed out the crucial importance of kidney stone analysis. Likewise, if possible, I analyse every stone because crystal type can change. But does this not raise the obvious question: How good are stone analysis labs? At first one might say why ask? We use labs all the time and trust them. As things turn out, stone analysis varies more in quality than serum electrolytes, or blood hemoglobin. Moreover, some stone crystals pose greater problems than others. There is a gold standard X Ray Diffraction Basiri et al recently reviewed all available papers concerning analysis of kidney stone crystals. Like prior investigators, some of whom they reference, X-ray diffraction does indeed reveal stone crystal structures … Continued
When I wrote the original article in 2014 limitations of proteomics seemed the main obstacle. This new work by Dr Frank Witzmann shows us the other side of the problem. A master of the modern proteomic techniques, with them Frank shows that the number of unique proteins in just two human calcium oxalate kidney stones is over 1,000. If inadequacy of technique stymied us two years ago, inadequacy of intellect – at least of mine – stymies at least me, now. What to make of so many proteins! What are they doing there? Which ones matter in stone genesis? We have the methods, we have stones to work on, but what shall we ask? As always, the magic is in the vision.
There is no doubt about what I say to patients: ” Analyse every kidney stone. Bring in any stones you have tucked in a dresser drawer and get them analysed. Bring me all the analyses that have been performed on your kidney stones.” But what do I say to me, and what do I do as time goes on and more stones form or are passed? Do I analyse every kidney stone? Do you? The problem of keeping track Whenever I get a new patient, the stone analyses are at the top of my mind. How can I do anything rational about prevention if I don’t know what the stone crystals are? If there are no analyses at the first … Continued
I do not know why anyone would diagnose distal RTA (dRTA) very often. As I will show you it has colorful and unusual characteristics as unmistakable as rare, so diagnosis is not difficult. But many more people think they have than have it. In my 50 years of kidney stone prevention I have perhaps a few dozen examples or so, out of many thousands of stone formers. This is another of those long, elaborate articles only the most devoted read. Even so, elaborate as it is, this article tells only part of the story. It simplifies or simply ignores the mechanism for low potassium in dRTA, and left for another time its genetic causes, and also the bone and mineral … Continued