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 reported by these very same names.
Being a bold and rather large graphic, the featured picture does what I intended, brings the main facts into view as, at a circus, the great animals and the small animals circle the ring by way of an introduction. Come. I will show you all the common stones, like at a fashion show, or a circus parade. You can watch as they go by and remind yourself, or wonder, which ones might have been yours.
Here they are.
Which type do you have?
You might think your doctors know what stones you have formed, but don’t rely on it. People move, doctors move, health records are far from ‘all electronic’. That stone report from 4 years ago could lie in a dusty filing cabinet, your new doctors unaware it exists. Worse, it could hide in a dresser drawer and you forgot it you put it there. Perhaps even more worse, the stones might stay in that drawer, never analysed at all. Find the stones, find missing reports, urge analysis by your physicians. They can help you most if they know your stone analysis.
When they do not know, physicians can still mount prevention efforts but with less focus and probably less effect than when guided by a knowledge of the crystals. So always seek treatment. If a stone comes along the way, make every effort to get it analysed.
Why should you care to know all this?
Because you will conduct much of your own treatment, and over many years.
Since stones tend to recur, prevention requires treatment over long periods. These treatments work by altering urine chemistry in a direction that minimizes the risk of forming crystals. Such altering of urine chemistry requires control of fluid intake, lifestyle, and diet, and sometimes additional use of medications.
Just as the sailor who aims along a chosen track against the random, misdirecting, confusing sea and air maintains a constant way in proportion to that skill which comes from knowing the way of the boat, patients who aim to keep a certain kind of condition in their urine despite the demands and temptations of the world do so, I believe, in proportion to skills that come from knowing how their work and lives and foods affect their bodies, and how those crystals form which they so much desire to prevent.
Put another way, knowledge is power.
Why is this article so long?
I wanted to put all five main types of kidney stones. That makes a long story. But probably you will care to read about only your own type.
I should mention here, to save a lot of confusion, that stones often contain mixtures of crystals.
The pie chart refers to the most common crystals in a stone, for which the stone is usually named. Much of the time, minor crystal components are not crucial, but sometimes – to jump forward a bit – they are. Even a trace of struvite or cystine, for example, can have great diagnostic importance.
Calcium stones
Calcium Oxalate Crystals
In the great circle atop this page article, the calcium oxalate stone, being most common, occupies a lion’s share of the space. 
The calcium oxalate crystal forms when calcium combines with oxalic acid. Oxalic acid (at left), a dead end waste product that the kidneys remove, contains two carbon atoms (the large black spheres), four oxygen atoms, and two hydrogen atoms (silver).
At the acidity of urine, the positively charged hydrogens leave their negatively charged oxygens. As a result the oxalate molecule carries two negative charges. In the figure at right one negatively charged oxygen attracts the hydrogen of a nearby water molecule (H – O -H) while another attracts a positively charged calcium atom.
You can imagine how another oxalate ion (the name for a charged molecule in water) could attract the same calcium, or another calcium atom attract the bottom oxygen on the oxalate molecule so the chain extends and makes a crystal. You can see more about this in a video I made. Broadly speaking – though my more expert colleagues may bridle at such a simplification – the calcium atoms and oxalate molecules combine by the attraction of their opposite charges.
The calcium oxalate kidney stone comes in two varieties, calcium oxalate monohydrate and calcium oxalate dihydrate. The former are harder and therefore more resistant to fragmentation by lithotripsy. Likewise, the former appear more often when elevated levels of urine oxalate are present.
Calcium oxalate stone formers
From Systemic Diseases
Sometimes this kidney stone arises from a systemic cause, like bowel disease, primary hyperparathyroidism, or primary hyperoxaluria. Only physicians can establish that a known disease – like bowel disease – is the cause of stones. Only physicians can discover underlying primary hyperparathyroidism as a cause of stones. Patients cannot do much for themselves except provide as complete a medical record as possible.
Idiopathic
Most of the time this kidney stone arises simply from the interplay between inheritance, diet, and aspects of daily living. We call such patients idiopathic calcium oxalate stone formers, from Greek ἴδιος idios “one’s own” and πάθος pathos “suffering”.
Even though physicians discover the links between daily living and stone production, and select those changes that can prevent new stones, patients themselves must create and maintain those changes. I believe patients can so this in proportion to how well they understand what is needed, and why. When changes in daily life are not enough, physicians add medications, so even then patients remain active therapists for their own disease.
Stones usually form on kidney surfaces
About one million nephron units make up a normal adult kidney. The calcium oxalate kidney stone type does not grow in the tubules of the nephrons but ‘outside’ them, on the surfaces of the renal pelvis where final urine collects and drains through the ureter to the bladder. Here is a video that shows how they can form.
Calcium phosphate crystals
Phosphate ion and urine pH
Calcium phosphate stone crystals form when calcium atoms combine with phosphoric instead of oxalic acid and produce the calcium phosphate kidney stone.
Phosphoric acid is simply a phosphorus atom (shown as the ‘P’ in the line drawing to the left) with 4 oxygen atoms bonded to it. One oxygen atom has two lines for its bond to phosphorus; this oxygen cannot provide any charge with which to bond calcium atoms to make a crystal. The other three have ordinary bonds that are shown by a line, and a dashed and solid arrow. These two arrows mean simply that the oxygens lie above and below the plane of the paper – so if you built the molecule with sticks and balls it would have a three dimensional shape.
One of the three negatively charged oxygens never has a hydrogen on it in urine but only in exceedingly acidic solutions. A second charged oxygen is always occupied by a hydrogen atom in urine.
This makes the third oxygen, variably occupied by a hydrogen in urine, a tie breaker.
In a urine of average normal acidity (pH around 6), most of the tie breaker oxygens have their hydrogen leaving the phosphate ion only one negative charge. Not enough to make a crystal.
When the urine is abnormally alkaline (pH above 6.3 or 6.5), the variable oxygen becomes charged so the ion has two negative charges that can combine with calcium to make crystals. For this reason the calcium phosphate kidney stone tends to occur in people who produce a more alkaline urine than those who produce calcium oxalate kidney stones.
Brushite vs. hydroxyapatite
Much like calcium oxalate, calcium phosphate crystals begin simply as one to one pairings of doubly negative phosphate ions with doubly positive calcium atoms. This initial crystal is named brushite. Brushite, which is an equal mixture of calcium and phosphate ions, can convert to hydroxyapatite (HA), which has a more unbalanced proportion of calcium to phosphate. Hydroxyapatite crystals make bones hard.
Because less soluble than brushite, hydroxyapatite cannibalizes brushite. The organic molecules in urine modify this process.
Calcium Phosphate stone formers
From Systemic diseases
Primary hyperparathyroidism and renal tubular acidosis raise average urine alkalinity (higher urine pH) and foster calcium phosphate kidney stones. Many uncommon genetic diseases do the same.
Idiopathic
Idiopathic calcium phosphate stone formers share a common set of traits. Perhaps because urine contains far more phosphate than oxalate, they form more frequent and larger stones than idiopathic calcium oxalate stone formers. Often the stones originate as crystal plugs at the terminal ends of the kidney tubules. More crystals deposit over the end of the plug open to the urine, to make the final stone. Crystal plugs damage the cells that line the tubules and cause local scarring.
Uric acid stones
Uric acid crystals
Structure and charged sites
A breakdown product of DNA and RNA, uric acid forms crystals in abnormally acidic (low pH) urine. Obese and diabetic people, those with gout or kidney disease typically produce abnormally acid urine. I know how the urine becomes acid, but leave it for elsewhere on the site.
Uric acid, the molecule we are interested in here (shown to the far right), has two linked rings made of carbon atoms (they are at the angles where lines join), with 
interposed nitrogen (N), oxygen (O), and hydrogen (H) atoms.
This molecule has only two charged sites, the nitrogen atoms at the bottoms of the rings. In urine of pH 6 or so, one nitrogen lacks its hydrogen and therefore carries a single negative charge. In more alkaline solutions both nitrogens lack hydrogens, but urine does not normally achieve such alkalinity (pH>8).
When urine pH is low (<5.5) and both nitrogens have their hydrogens, the molecule lacks any charged site, so water can no longer find a hold on the molecule. It crystallizes. It simply leaves the water as water droplets themselves form from the high and vaporous late afternoon clouds and fall from the air as the warm rains of springtime.
Relation to water
Water molecules are each a single oxygen atom (large ball) bonded with two hydrogen atoms (small balls) as in this picture from Wikipedia. The hydrogen side has a positive, the bare side of the oxygen a negative charge. So water molecules link to each other, 
positives to negative surfaces, to make up the clear and seemingly continuous fluid we drink, swim in, and hold up umbrellas to keep off of us when it rains. They link by charge at angles, shown by the number ‘1’ so as to make up a three dimensional macrame.
To be ‘in solution’ means to have some charge to which water molecules can link up with by attraction. Calcium atoms are positive and become surrounded by a shell of water molecules facing it with their bare negative surfaces. Oxalic and phosphoric acids have negative charges and are surrounded by water molecules pointing their positive or hydrogen sides to them.
Uric acid at neutral pH has its one negatively charged nitrogen water can grasp. But when pH falls, and neither nitrogen has any extra charge for water to bind with, how can the molecule remain among the water molecules? It cannot. The molecules stack into solid crystals and fall from solution.
Uric acid stone formers
The stones can be orange – red, large, and numerous
The stones can be red or orange because uric acid crystals absorb hemoglobin breakdown products that are red – orange pigments in urine. Sometimes uric acid crystals pass in urine as a red orange gravel.
Uric acid does not have to connect itself to some other atom or molecule to make a crystal, in the way that calcium must bond with oxalate or phosphate ions to make calcium oxalate or calcium phosphate crystals. When pH is low enough to extinguish its charge, uric acid can crystallize very fast, in seconds, and pass as an orange gravel in the urine. If retained, such crystals can grow rapidly into large stones. Because there is much more uric acid in urine than there is oxalic acid, uric acid stones can grow very large and rapidly. Some fill up the entire collecting system of the kidney.
Urine pH controls stone formation
But because the whole process depends almost completely on the acidity of the urine, uric acid stones are very easy to treat. Just a modest amount of supplemental alkali will make the urine of almost any patient alkaline enough that the hydrogen atoms are removed from the one crucial charged nitrogen. Water can bond there so uric acid remains in solution. Because so simple, treatment prevents stones with certainty. Relapse need never occur.
Mixed stones require special care
Unfortunately, however, stones commonly contain uric acid mixed with calcium oxalate. In this case, one needs to track down the cause of the calcium oxalate stones as well as make the urine alkaline enough to stop uric acid stones from forming. Calcium phosphate crystals mix with uric acid only rarely, because it takes a rather alkaline urine to remove the hydrogen atoms from phosphate so it has two negative charges and can bind efficiently with calcium atoms. At that higher pH, uric acid will have its charge site and remain in solution.
Struvite stones
Urea and the planet
Kidneys cannot make struvite. Bacteria make it. Not all bacteria, either. It takes bacteria that normally thrive in the soil, and they do it for ancient and compelling reasons. These bacteria produce the kidney stone named Struvite after Heinrich Christian Gottfried von Struve (1772–1851).
Animals deposit urea (at left) all over the planet when they urinate. Plants cannot use it.
Like oxygen, nitrogen is an essential for life yet dangerous. It is integral to proteins, DNA and RNA. As these molecules are broken down and remade, some of their nitrogen slips by and can form poisonous compounds unless caught up in safe waste products. Of these, the main one, urea, contains 2 nitrogen atoms bound to a single carbon atom (‘C’ in the picture to your left).
Uric acid contains 4 nitrogen atoms (look back at the picture of it). Birds and reptiles excrete most of their nitrogen as uric acid; mammals like us excrete nitrogen mainly as urea.
As the animals of the world urinate on the soil, their urea brings nitrogen to plant roots, but the plants cannot use it. They cannot release the nitrogens from the carbon atom that holds them. Those soil bacteria that make struvite crystals have an enzyme, called urease, that can release the nitrogen for plants to use as their nitrogen supply.
So, soil bacteria with urease maintain the nitrogen cycle of the earth.
Struvite crystals
As they release nitrogen from its carbon in urea, the nitrogen takes up a proton making ammonia (NH3). Ammonia is a powerful alkali and takes up another proton.
As it does so, the working bacteria surround themselves with spheres of very alkaline fluid enriched with ammonium ion (NH4) that carries one positive charge. Soil magnesium ( an atom with two positive charges) and phosphate sans all of its protons (an ion with three negative charges) spontaneously form their triple salt: three negative phosphate charges, two positive from magnesium, one positive from NH4).
The crystals anchor the bacteria and help create a porous nitrogen rich soul good for plants to grow in
The struvite kidney stone
Why they start
Because urine is filled with urea, soil bacteria that get into the urinary tract can break it down to ammonia and create struvite from the magnesium and phosphate urine always contains.
You might wonder how soil bacteria get into the urinary system.
Because we eat them, with foods that are not cooked, and they become part of the intestinal bacterial population from an early age. In us and around us, they find a way into the urinary system, especially in women whose shorter urethra makes entry easier. No matter how skillfully used, any instrument put into the bladder can carry our personal soil bacteria with it.
What they do
Because they live among molds and fungi, soil bacteria easily mount resistances to antibiotics, so antibiotics given for a urinary tract infection will tend to kill sensitive bacteria and select out those that can resist them.
Soil bacteria can produce struvite stones de novo, or infect calcium stones to produce a mixed stone. Either way, struvite stones are infected by their very nature. They can become huge. Their bacteria can injure the kidneys, even enter the bloodstream and cause sepsis.
Treatment is a mix of thoughtful surgery and selection of antibiotics after such surgery to kill bacteria that remain. If the stones are a mixture of struvite and calcium crystals, new calcium stones need to be prevented.
Cystine stones
Inherited kidney abnormality
Lemon yellow with a sugary coating these form only in people who have an inherited kidney disorder called cystinuria.
Although the kidneys function well, they permit abnormal amounts of four amino acids to enter the urine. Three do not matter that we know of. The fourth makes crystals and the cystine kidney stone type.
Cystine
Cystine (left) forms through the coupling of two identical amino acids – called cysteine – through their sulfur atoms (‘S’ in the line drawing).
Each cysteine contains two carbon atoms – not shown except as corners – bonded together (shown by the single long line that connects the two corners) as in oxalic acid.
One carbon atom has 2 oxygens bonded to it; the other has one nitrogen (which makes it an amino – nitrogen containing – acid), a hydrogen atom, and a sulfur atom. As for phosphate, the dashed and solid arrows simply mean the hydrogens and sulfurs lie above and below the plane of the page and a stick model would have a three dimensional shape.
Cystine Crystals
Cysteine itself is very soluble because the sulfur atom has an appreciable negative charge.
But the big, long cystine molecule has very little charge because the sulfurs bind to each other. So, like uric acid, cystine loses intimacy with water molecules and simply leaves the solution as crystals. Also like uric acid, the process is fast.
Cystine stones
Because people with cystinuria lose large amounts of cystine in their urine stones readily grow large, and fast.
Stones probably form in the urine itself. But cystine crystals can plug the ends of kidney tubules, as calcium phosphate crystals do, causing cell damage.
Since cystinuria is an inherited disease, stones may begin in childhood.
Effective treatment always requires very large amounts of fluids to dilute the urine. The few effective drugs resemble cysteine. Their sulfur groups bond with cysteine to form a ‘mixed disulfide’ more soluble than cystine. But their side effects can limit use.
Rare stones
Here and there we find patients who make uncommon crystals and require very special care.
Uric acid, as an example, can form odd crystals such sodium or ammonium acid urate, especially in people with bowel disease and chronic diarrhea.
Anti-viral drugs can crystallize in urine and form stones only recognized for what they are through stone analysis.
Very rare disorders of metabolism can produce molecules which crystallize in the urine, for example 2-8 dihydroxyadenine.
Although it can take a while before the right answer emerges, stone analyses will put physicians on the right track for these special cases.
The end of a very long post
That’s my parade.
The common animals and the rarer animals have gone by, and you have glimpsed the main ones, big and small.
The one point is what it was at the beginning. Each kind of kidney stone has its own ways, and treatment requires we know which one you have.
Likewise, for whatever that one may be, it is good to know as much about it as you can know. For long term prevention of stones is hard to come by and ultimately what the patience and and consistency of patients themselves matters most.
If you don’t know which stones you have made, find out.
Track down old reports and pull them together.
Keep copies and send everything to the doctors who care for you.
Fred Coe MD
Hello Dr. Coe, I’m Beth a 64 yr. Old white female dx. with MS 23 yrs. Ago. Due to neurogenic bladder=urostomy 6 yrs. Ago. Most of my lesions are in spinal cord. 2 yrs. Ago had a stone lodged in left ureter unaware bc no pain. Annual urology check up & hydronephrosis left kidney=Or stone removed via kidney. June 2021 urologist stated 3 stones left kidney & 1 IN right kidney. Researched & read were MS pts. Like folks with spinal cord nerve damage =stones. I do not eat dairy or red meat. I drink dly 48 to 60 ozs Of h2o dly. They cannot due a bone density test=osteoporosis-calcium?
Hi Beth, I guess the obstruction damaged the left kidney and you have one in the right kidney. You must find out what is causing the stones and act to prevent more. This chapter gives a very good overview of what to do, beginning with what the stones were that were removed. I would study it and make a plan so more stones do not form. Regards, Fred Coe
Dr. Coe, I make thousands of kidney stones. Uric Acid and Oxalate stones to be precise. I have passed over 20,000 stones since 2005 and I have had 5 surgeries during which several thousand more stones have been removed, with the largest being 32 cm. I make these stones even when my PH is neutral. I was diagnosed with Crohns Disease in 2007 but multiple Dr’s including Dr. Scott Lee at UW insist the stones are not related to the Crohns. They have determined that the likely cause of the stones is the rapid breakdown of red blood cells or muscle tissue . At first they thought it was a type of porphyria and I have had multiple positive PBG urine tests but the generic tests were negative. They have also looked at ALS and CLL, but they have ruled them both out. I have also had several instances of Rhabdo which is why they are thinking it is either a blood or muscle v disorder. We are currently at a point where they are saying the only option may be going to the Mayo Clinic for 28 days for tests which unfortunately would be considerably expensive even with insurance.
My question is, have you ever seen any underlying medical condition that can cause this kind of rapid stone formation other than porphyria? All of the nephrologists and urologists who have evaluated my condition have said they have never seen anything like it and the purple color of my urine points to porphyria but hematology insists that’s not possible either.
Thank you for your time.
Hi Chad, I cannot help much with the porphyria and purple urine issue, but I also cannot imagine how uric acid crystals can form in a urine of neutral (does that mean 6 or 7?) pH. The crystals are not stable. Perhaps the crystallography of the stones is inaccurate because they are very unusual. If so, it is best to start with submitting the stones to Mayo – they have a fine stone lab – or another special lab like Litholink that now does stones. Likewise, what are the 24 hour urine supersaturations for calcium oxalate? Are they high, and for what reason? Regards, Fred Coe
Dr. Coe, I make thousands of kidney stones. Uric Acid and Oxalate stones to be precise. I have passed over 20,000 stones since 2005 and I have had 5 surgeries during which several thousand more stones have been removed, with the largest being 32 cm. I make these stones even when my PH is neutral. I was diagnosed with Crohns Disease in 2007 but multiple Dr’s including Dr. Scott Lee at UW insist the stones are not related to the Crohns. They have determined that the likely cause of the stones is the rapid breakdown of red blood cells or muscle tissue . At first they thought it was a type of porphyria and I have had multiple positive PBG urine tests but the generic tests were negative. They have also looked at ALS and CLL, but they have ruled them both out. I have also had several instances of Rhabdo which is why they are thinking it is either a blood or muscle v disorder. We are currently at a point where they are saying the only option may be going to the Mayo Clinic for 28 days for tests which unfortunately would be considerably expensive even with insurance.
My question is, have you ever seen any underlying medical condition that can cause this kind of rapid stone formation other than porphyria? All of the nephrologists and urologists who have evaluated my condition have said they have never seen anything like it and the purple color of my urine points to porphyria but hematology insists that’s not possible either.
Thank you for your time.
Hi Chad, I cannot help much with the porphyria and purple urine issue, but I also cannot imagine how uric acid crystals can form in a urine of neutral (does that mean 6 or 7?) pH. The crystals are not stable. Perhaps the crystallography of the stones is inaccurate because they are very unusual. If so, it is best to start with submitting the stones to Mayo – they have a fine stone lab – or another special lab like Litholink that now does stones. Likewise, what are the 24 hour urine supersaturations for calcium oxalate? Are they high, and for what reason? Regards, Fred Coe
Dr. Coe,
In regards to infection and stones, does a regular urine culture show all infections that could cause certain stones or are there certain other urine tests that must be ordered especially if someone doesn’t have any urinary symptoms of infection.
Hi C, No. There are fastidious organisms that escape routine culture. One clue to an infection that can produce stones is a marked excess of ammonia in a urine of high pH – a 24 hour kidney stone urine will disclose this. Regards, Fred Coe
Dr. Coe,
In regards to infection and stones, does a regular urine culture show all infections that could cause certain stones or are there certain other urine tests that must be ordered especially if someone doesn’t have any urinary symptoms of infection.
Hi C, No. There are fastidious organisms that escape routine culture. One clue to an infection that can produce stones is a marked excess of ammonia in a urine of high pH – a 24 hour kidney stone urine will disclose this. Regards, Fred Coe
I went to emergency room in Oct 2018 due to kidney stone. I had a procedure to take out the kidney stones.
But in April 2021, during a routine ultrasound check up, doctor found out that I had a 3cm by 2 cm stagnorn stone. So I had Percutaneous nephrolithotomy in July 2021.
stone analysis says it is Carbonate Apatite (Dahllite) 100%. My urologist also did a urine culture for all possible bacteria, but results came back to be all negative. So it is baffling what is causing me have recurrent stones.
I will be doing a 24-hour urine collection soon.
What kind of stone is Carbonate Apatite (Dahllite) 100%? How can I prevent in the future.
Thank you very much.
Hi QW, it is a variety of calcium phosphate stone, with its own special issues. The main causes are high urine calcium (genetic) and high urine pH, the latter driven by complex mechanisms. Your serum and 24 hour urine testing will reveal the causes, so you can plan prevention. Regards, Fred Coe
I went to emergency room in Oct 2018 due to kidney stone. I had a procedure to take out the kidney stones.
But in April 2021, during a routine ultrasound check up, doctor found out that I had a 3cm by 2 cm stagnorn stone. So I had Percutaneous nephrolithotomy in July 2021.
stone analysis says it is Carbonate Apatite (Dahllite) 100%. My urologist also did a urine culture for all possible bacteria, but results came back to be all negative. So it is baffling what is causing me have recurrent stones.
I will be doing a 24-hour urine collection soon.
What kind of stone is Carbonate Apatite (Dahllite) 100%? How can I prevent in the future.
Thank you very much.
Hi QW, it is a variety of calcium phosphate stone, with its own special issues. The main causes are high urine calcium (genetic) and high urine pH, the latter driven by complex mechanisms. Your serum and 24 hour urine testing will reveal the causes, so you can plan prevention. Regards, Fred Coe
I had a 8mm stone removed by lithotripsy 2 months ago. Report said it was 60% carbonate apatite, 30% calcium oxalate dihydrate and 10% calcium oxalate mono hydrate. I know I have more stones in both kidneys and have been to the ER 3 times in the last month due to severe pain (radiating along femoral nerve track) on my right side and blood in my urine. Every time the CT scan has shown that the stones are still in my kidney ( biggest in mid pole) so I have been discharged with pain killers that do not work. Can this type of radiating pain (severe enough that I would say they are close to labour pains but worse because they last longer) be related to stones that are non- obstructing and inside the kidney?
Hi Jes, Yes. They can move and obstruct within the kidney, for example. Your stones are high in phosphate content – carbonate apatite – and can grow rather rapidly, and crystals can form that cause pain just like stones. So prevention is paramount. Here is a good start in planning a prevention program, and I urge you consider it. Regards, Fred Coe
I had my first stone, 80% Calcium Oxalate Monohydrate that caused a forniceal rupture. I do not want this experience again! I have a fairly healthy diet and drink only water and alot of it. We spent time in Italy a couple of months ago. Could a diet change have caused something like this and this quickly?
2mm stone
Hi Al, my comment is unchanged. Fred
Hi Al, Italy may have helped, but stone formation is a chronic disease that usually involves some underlying causes. You would be best served by a full evaluation to find out what may have caused your stone and take steps to prevent more. As for timing, the stone could have been silent in your kidney for months or even years before it made its presence known by obstructing. Regards, Fred Coe
I had my first stone, 80% Calcium Oxalate Monohydrate that caused a forniceal rupture. I do not want this experience again! I have a fairly healthy diet and drink only water and alot of it. We spent time in Italy a couple of months ago. Could a diet change have caused something like this and this quickly?
2mm stone
Hi Al, my comment is unchanged. Fred
Hi Al, Italy may have helped, but stone formation is a chronic disease that usually involves some underlying causes. You would be best served by a full evaluation to find out what may have caused your stone and take steps to prevent more. As for timing, the stone could have been silent in your kidney for months or even years before it made its presence known by obstructing. Regards, Fred Coe
Hi, I got 2cm kidney stone removed through urs and eswl. and stone analysis result is calcium carbonate. What is the cause to avoid recurring.
Hi Diana, It means you probably form calcium phosphate stones, and they pose special problems. Here is a good review of that kind of stone patient.Regards, Fred Coe
First, you are skilled at writing. I just found this blog and you made me laugh- a rare feat while dealing with kidney stones!
Second, I wish I had been able to catch my stone. Do you have any tips for finding a doctor who is willing to analyze the stone? This far, I’ve yet to find one.
Hi Jen, How nice you are! As for the stone, I wish you had not lost it. If you get another chance any physician can order a stone analysis. Litholink, the common source for kidney stone 24 hour urine testing does stone analyses, for example. So, try harder, and give the stone to your physician and tell her/him to get it analyzed. Fred
First, you are skilled at writing. I just found this blog and you made me laugh- a rare feat while dealing with kidney stones!
Second, I wish I had been able to catch my stone. Do you have any tips for finding a doctor who is willing to analyze the stone? This far, I’ve yet to find one.
Hi Jen, How nice you are! As for the stone, I wish you had not lost it. If you get another chance any physician can order a stone analysis. Litholink, the common source for kidney stone 24 hour urine testing does stone analyses, for example. So, try harder, and give the stone to your physician and tell her/him to get it analyzed. Fred
Hi I just spent almost 2 weeks dealing with ER visits and my right kidney was completely closed off from urinating by a 5mm, 60% Calcium Oxalate Dihydrate, 20% Calcium Oxalate Monohydrate, and 20% Carbonate Apitate stone for btwn 8 and 11 days now my kidneys and liver function tests are not right and my Primary Care Dr is recommending me to stop my cholesterol medications, but I also suffer from Graves disease which I had RAI therapy for in 2019 so have been hypothyroid since fall/winter of 2019 and have been on hormone replacement therapy for this as well….the problem now is I dont understand what this means in reference to my health I am already dealing with alot of issues and I’m only 36 almost 37 and recent tests are also showing blockages in my heart as well as spinal cord damage something called hydrosyringomyelia without definite cord expansion and I dont know if this could in any way be related to the endosalpingiosis I had removed last year along with the Salipingectomy I also had last year after the removal of the endosalpingiosis that had attached itself to my inner stomach lining by my fallopian tube.
Hi Andrea, You seem to have many problems, some beyond what this site concerns. Certainly the right kidney needs treatment to restore drainage – I imagine the stone has been passed or removed. Kidney function may have been reduced by the obstruction of the right kidney and will hopefully rise over the next few weeks. The liver abnormalities should not be from stones. Likewise for the heart and spinal cord problems. For the stones, here is a good place to begin concerning prevention. The article outlines what one needs to do in order to create a prevention program. Regards, Fred Coe
Hi I just spent almost 2 weeks dealing with ER visits and my right kidney was completely closed off from urinating by a 5mm, 60% Calcium Oxalate Dihydrate, 20% Calcium Oxalate Monohydrate, and 20% Carbonate Apitate stone for btwn 8 and 11 days now my kidneys and liver function tests are not right and my Primary Care Dr is recommending me to stop my cholesterol medications, but I also suffer from Graves disease which I had RAI therapy for in 2019 so have been hypothyroid since fall/winter of 2019 and have been on hormone replacement therapy for this as well….the problem now is I dont understand what this means in reference to my health I am already dealing with alot of issues and I’m only 36 almost 37 and recent tests are also showing blockages in my heart as well as spinal cord damage something called hydrosyringomyelia without definite cord expansion and I dont know if this could in any way be related to the endosalpingiosis I had removed last year along with the Salipingectomy I also had last year after the removal of the endosalpingiosis that had attached itself to my inner stomach lining by my fallopian tube.
Hi Andrea, You seem to have many problems, some beyond what this site concerns. Certainly the right kidney needs treatment to restore drainage – I imagine the stone has been passed or removed. Kidney function may have been reduced by the obstruction of the right kidney and will hopefully rise over the next few weeks. The liver abnormalities should not be from stones. Likewise for the heart and spinal cord problems. For the stones, here is a good place to begin concerning prevention. The article outlines what one needs to do in order to create a prevention program. Regards, Fred Coe
Hi Dr. Coe,
I had laser lithotripsy to treat a staghorn stone one year ago. A CT scan showed a 9 x 8 mm
stone in the lower pole of the left kidney. There was also a smaller stone in the midpole calyx. The lab result from stone examination said : “CALCIUM OXALATE MONO/DIHYDRATE AND SMALL AMOUNTS OF CALCIUM
CARBONATE/PHOSPHATE WITH MAGNESIUM AMMONIUM PHOSPHATE”
I had a few small stones in 2016 (ER visit and imagery for diagnosis but resolved without treatment or noticeable passing of stones) and similarly in 1995 though I don’t recall being told how many stones I may have had then- I didn’t notice passing any stones afterwards and went 20+ years without any other incidents.
I had an ultrasound 2 weeks ago in preparation for a checkup with the urologist late April. The technician wouldn’t say much but indicated stones in both kidneys. I know my father had at least one stone and my brother has just passed one so I am curious if the analysis and the family history point in any particular direction. Thank you for your great content!
Hi Mark, Alas you form calcium oxalate stones and really need to take action to prevent more. Here is my very best on that – I hope it helps. It is about making a programmatic effort based on a full evaluation of causes. Take a look, and given what you have said, strongly consider pursuing prevention. Regards, Fred Coe
Hi Dr. Coe,
I had laser lithotripsy to treat a staghorn stone one year ago. A CT scan showed a 9 x 8 mm
stone in the lower pole of the left kidney. There was also a smaller stone in the midpole calyx. The lab result from stone examination said : “CALCIUM OXALATE MONO/DIHYDRATE AND SMALL AMOUNTS OF CALCIUM
CARBONATE/PHOSPHATE WITH MAGNESIUM AMMONIUM PHOSPHATE”
I had a few small stones in 2016 (ER visit and imagery for diagnosis but resolved without treatment or noticeable passing of stones) and similarly in 1995 though I don’t recall being told how many stones I may have had then- I didn’t notice passing any stones afterwards and went 20+ years without any other incidents.
I had an ultrasound 2 weeks ago in preparation for a checkup with the urologist late April. The technician wouldn’t say much but indicated stones in both kidneys. I know my father had at least one stone and my brother has just passed one so I am curious if the analysis and the family history point in any particular direction. Thank you for your great content!
Hi Mark, Alas you form calcium oxalate stones and really need to take action to prevent more. Here is my very best on that – I hope it helps. It is about making a programmatic effort based on a full evaluation of causes. Take a look, and given what you have said, strongly consider pursuing prevention. Regards, Fred Coe
Hi,
I am 23M who recently passed two stones both 3mm in size, about a month apart (April and May), and was dealing with them since May ‘21. While passing first stone, showed bacteria in urine, but after passing first stone and throughout course of passing second stone, no bacteria in urine. Got the first stone tested and it just came back as 65% Calcium Oxalate Dihydrate (Weddellite) and 35% Carbonate
Apatite (Dahllite). What would you recommend to me going forward? Before stone diagnosis, I know I wasn’t drinking enough water, and I previously had a high protein diet with a lot of almonds in my diet. Thanks!
Hi Mike, the stones suggest a high urine calcium and alkaline pH. I would certainly get a complete evaluation with 24 hour urines and bloods. High oxalate would produce calcium oxalate monohydrate stones, and never Dahlite. Do it. Regards, Fred Coe
Hi,
I am 23M who recently passed two stones both 3mm in size, about a month apart (April and May), and was dealing with them since May ‘21. While passing first stone, showed bacteria in urine, but after passing first stone and throughout course of passing second stone, no bacteria in urine. Got the first stone tested and it just came back as 65% Calcium Oxalate Dihydrate (Weddellite) and 35% Carbonate
Apatite (Dahllite). What would you recommend to me going forward? Before stone diagnosis, I know I wasn’t drinking enough water, and I previously had a high protein diet with a lot of almonds in my diet. Thanks!
Hi Mike, the stones suggest a high urine calcium and alkaline pH. I would certainly get a complete evaluation with 24 hour urines and bloods. High oxalate would produce calcium oxalate monohydrate stones, and never Dahlite. Do it. Regards, Fred Coe
I finally got the results back and my latest kidney stone was Carbonate apatite (Dahllite)… What does this mean?
Hi Alex, That is a calcium phosphate stone, and this article is about the issues of preventing such stones. Regards, Fred Coe
Hello Doctor Coe,
I recently started getting kidney stones after undergoing gastric sleeve surgery. I was finally able to catch one and have it analyzed. The following are the results:
• Calcium Oxalate Monohydrate: 6
• Calcium Oxalate Dihydrate: 70
• Calcium Phosphate Carbonate: 24
The stone measured at 4.0 x 3.0 x 3.0 mm in size.
I have a follow-up appointment with my physician scheduled, but he can be a bit confusing. I would really like to be prepared for the visit by doing a bit of research beforehand. With this said, I have a couple questions, should you have the time (and desire) to provide feedback:
1. When researching this stone, should I concentrate more on the Weddellite result, since it’s what was primarily found in my stone? By this I mean, should I be researching diets and things I can do to reduce the occurrence of Weddellite stones?
2. Does the measurement mean that I had a 4mm stone? Before passing it, I was told it was a 3mm.
I have been in the ER every other weekend for months on end, at least up until finally passing this last one. I currently have a 4mm stone in my left kidney (which isn’t causing any discomfort) and so many in my right kidney that they cannot count them. The right kidney makes my back feel as though I have a mild rib fracture. I have been told that the stones on the right are all under 3mm.
I’m 36 years old and have always been in good health. No comorbities, aside from obesity, and I’m currently down 91+ pounds. I had sepsis in October 2021 and again in December 2022. December was when my first kidney stone was discovered. My surgery was in January 2022. Since then, I have had stone after stone. It’s just no way to live.
If you have any thoughts or feedback for me, I would love to get your opinion. Thank you for all the information that you provide and for following up with so many of us. Your generosity of time and information is absolutely invaluable.
Sincerely,
Meghan
Hi Meghan, Calcium oxalate monohydrate usually forms when urine calcium is high; the calcium phosphate stone usually means urine is unduly alkaline. You should have at least 2 24 hour urine collections for stone risk which will tell you what is causing the stones. Gastric sleeve sometimes limits fluids so urine volume is low. Rarely it raises urine oxalate. The only way to plan treatment is to have the urine studies.Prevention is often rather successful when aimed at specific abnormalities. Regards, Fred Coe
Hello Doctor Coe,
I recently started getting kidney stones after undergoing gastric sleeve surgery. I was finally able to catch one and have it analyzed. The following are the results:
• Calcium Oxalate Monohydrate: 6
• Calcium Oxalate Dihydrate: 70
• Calcium Phosphate Carbonate: 24
The stone measured at 4.0 x 3.0 x 3.0 mm in size.
I have a follow-up appointment with my physician scheduled, but he can be a bit confusing. I would really like to be prepared for the visit by doing a bit of research beforehand. With this said, I have a couple questions, should you have the time (and desire) to provide feedback:
1. When researching this stone, should I concentrate more on the Weddellite result, since it’s what was primarily found in my stone? By this I mean, should I be researching diets and things I can do to reduce the occurrence of Weddellite stones?
2. Does the measurement mean that I had a 4mm stone? Before passing it, I was told it was a 3mm.
I have been in the ER every other weekend for months on end, at least up until finally passing this last one. I currently have a 4mm stone in my left kidney (which isn’t causing any discomfort) and so many in my right kidney that they cannot count them. The right kidney makes my back feel as though I have a mild rib fracture. I have been told that the stones on the right are all under 3mm.
I’m 36 years old and have always been in good health. No comorbities, aside from obesity, and I’m currently down 91+ pounds. I had sepsis in October 2021 and again in December 2022. December was when my first kidney stone was discovered. My surgery was in January 2022. Since then, I have had stone after stone. It’s just no way to live.
If you have any thoughts or feedback for me, I would love to get your opinion. Thank you for all the information that you provide and for following up with so many of us. Your generosity of time and information is absolutely invaluable.
Sincerely,
Meghan
Hi Meghan, Calcium oxalate monohydrate usually forms when urine calcium is high; the calcium phosphate stone usually means urine is unduly alkaline. You should have at least 2 24 hour urine collections for stone risk which will tell you what is causing the stones. Gastric sleeve sometimes limits fluids so urine volume is low. Rarely it raises urine oxalate. The only way to plan treatment is to have the urine studies.Prevention is often rather successful when aimed at specific abnormalities. Regards, Fred Coe
I got my kidney stone analysis that shows 40% carbonate apatite, 31% ammonium urate and 29% struvite. I don’t know if I should be taking uric acid medic or high alkaline medic.
Hi Ammar, This is in answer to both of your questions. Your stone contains struvite which is usually produced by bacteria. It also contains ammonium urate that is more common when there is constant potassium and alkali loss from the GI tract as in bowel disease or laxative use. So all I can offer right now is that a lot depends on urine cultures and your clinical history neither of which I have available. Regards, Fred Coe
Hi Dr. Fred, thanks for your response. Actually I’ve got a mitrofanoff and bladder augmentation. Recently I did my urine culture, found the abnormal values in (Hemoglobinuria 1+, Leucocytes 3+, Erythrocytes 8/hpf, wbcs 64/hpf, bacteria 2+, yeast cells 2+, Albumin urine 80, albumin/creatinine ratio 30) and bacteria was Eschericia Coli(ESBL), so got my medication for the bacteria nitrofurantoin. I am very confused since the Urologists here are not consistent on one thing some says that ESWL isn’t an option because of mitrofanoff, pcnl is solution and others say ESWL is best. I am so much confused to what should I do.
Hi Ammar, This fits reasonably well with what I thought before. The procedure does predispose to infection, which could produce the struvite. I presume the stone was in the kidneys. Bladder stones are altogether different in management. As for SWL I cannot have an opinion, it depends on the exact anatomy and clinical situation which only your physicians know about. E Coli almost never produce struvite as they lack urease enzyme, so if the stone analysis is accurate there are other organisms that have not appeared in the cultures. Regards, Fred Coe
I got my kidney stone analysis that shows 40% carbonate apatite, 31% ammonium urate and 29% struvite. I don’t know if I should be taking uric acid medic or high alkaline medic.
Hi Ammar, This is in answer to both of your questions. Your stone contains struvite which is usually produced by bacteria. It also contains ammonium urate that is more common when there is constant potassium and alkali loss from the GI tract as in bowel disease or laxative use. So all I can offer right now is that a lot depends on urine cultures and your clinical history neither of which I have available. Regards, Fred Coe
Hi Dr. Fred, thanks for your response. Actually I’ve got a mitrofanoff and bladder augmentation. Recently I did my urine culture, found the abnormal values in (Hemoglobinuria 1+, Leucocytes 3+, Erythrocytes 8/hpf, wbcs 64/hpf, bacteria 2+, yeast cells 2+, Albumin urine 80, albumin/creatinine ratio 30) and bacteria was Eschericia Coli(ESBL), so got my medication for the bacteria nitrofurantoin. I am very confused since the Urologists here are not consistent on one thing some says that ESWL isn’t an option because of mitrofanoff, pcnl is solution and others say ESWL is best. I am so much confused to what should I do.
Hi Ammar, This fits reasonably well with what I thought before. The procedure does predispose to infection, which could produce the struvite. I presume the stone was in the kidneys. Bladder stones are altogether different in management. As for SWL I cannot have an opinion, it depends on the exact anatomy and clinical situation which only your physicians know about. E Coli almost never produce struvite as they lack urease enzyme, so if the stone analysis is accurate there are other organisms that have not appeared in the cultures. Regards, Fred Coe
My stone is such a mixture
20% calcium oxylate dihydrate
60% calcium oxylate monohydrate
20% carbonate apatite
??
Hi Darlene, Not really, it is 80% calcium oxalate (2 different forms of it) and 20% calcium phosphate. I would suggest you pursue the conventional evaluation for cause and get a rational treatment program from that. Regards, Fred Coe
Several years ago I had a very rare kidney stone removed. The doctor told me that he has never seen one before and probably would never see another. All I can remember is that it started with an X. Do you know the name of the stone I am talking about?
Hi Judy, I suspect it was a xanthine stone which usually arises from inherited deficiency of a key enzyme. Here is a lay person article that is quite good. Here is a recent fancy article. You need special testing, and if you have the problem proper treatment. It is specialized so if you tell me where you live I can try to suggest a convenient institution to help. Regards, Fred Coe
Several years ago I had a very rare kidney stone removed. The doctor told me that he has never seen one before and probably would never see another. All I can remember is that it started with an X. Do you know the name of the stone I am talking about?
Hi Judy, I suspect it was a xanthine stone which usually arises from inherited deficiency of a key enzyme. Here is a lay person article that is quite good. Here is a recent fancy article. You need special testing, and if you have the problem proper treatment. It is specialized so if you tell me where you live I can try to suggest a convenient institution to help. Regards, Fred Coe
Hi Dr. Coe-
I’m a 70yo male who has had two surgeries over the last 3 years to remove kidney stones from my left kidney. Stone analysis:
12/2019 Stones
Calcium Oxalate Dihydrate (Weddellite) 20%
Calcium Oxalate Monohydrate (Whewellite) 80%
09/2022 Stones (3 stones)
Calcium Oxalate Dihydrate (Weddellite) 25%
Carbonate Apatite (Dahllite) 50%
Ammonium-Magnesium Phosphate Hexahydrate (Struvite)25%
Prior to the 09/2022 surgery, urine cultures done 5/2022 and 9/2022 isolated Staph Lugdensis >100000 CFU/ml.
Questions:
1. Do the stone compositions indicate different pathways for stone production in 2019 and 2022?
2. Is it reasonable to link Staph Lugdensis infection to the Struvite formation? I was prescribed a course of ciproflaxicin in May and cephalexin in September to treat the UTI. Are additional antibiotic treatments indicated in light of the struvite findings?
Thank you
Hi William, The stones do differ. The first is a common calcium oxalate stone. The second has abundant calcium phosphate and also struvite. This latter may well have arisen because of infection. The organism you mention does not produce struvite stones, but they may be others that culture has not as yet identified. Your physicians can measure urine pH and ammonia which if both high support the presence of bacteria possessing urease and capable of producing struvite. Infection stone is a complicated surgical /medical condition, and I am sure your physicians have worked out a strategy suitable to your specific situation. Regards, Fred Coe
Hi Dr. Coe-
I’m a 70yo male who has had two surgeries over the last 3 years to remove kidney stones from my left kidney. Stone analysis:
12/2019 Stones
Calcium Oxalate Dihydrate (Weddellite) 20%
Calcium Oxalate Monohydrate (Whewellite) 80%
09/2022 Stones (3 stones)
Calcium Oxalate Dihydrate (Weddellite) 25%
Carbonate Apatite (Dahllite) 50%
Ammonium-Magnesium Phosphate Hexahydrate (Struvite)25%
Prior to the 09/2022 surgery, urine cultures done 5/2022 and 9/2022 isolated Staph Lugdensis >100000 CFU/ml.
Questions:
1. Do the stone compositions indicate different pathways for stone production in 2019 and 2022?
2. Is it reasonable to link Staph Lugdensis infection to the Struvite formation? I was prescribed a course of ciproflaxicin in May and cephalexin in September to treat the UTI. Are additional antibiotic treatments indicated in light of the struvite findings?
Thank you
Hi William, The stones do differ. The first is a common calcium oxalate stone. The second has abundant calcium phosphate and also struvite. This latter may well have arisen because of infection. The organism you mention does not produce struvite stones, but they may be others that culture has not as yet identified. Your physicians can measure urine pH and ammonia which if both high support the presence of bacteria possessing urease and capable of producing struvite. Infection stone is a complicated surgical /medical condition, and I am sure your physicians have worked out a strategy suitable to your specific situation. Regards, Fred Coe
Very fascinating. I am a 71-year-old man, non-drinker, non-smoker with a 9.5mm lower pole non-obstructing nephrolith of LEFT kidney as seen on a recent CT scan. The stone has been there for many years without issue. Both my former and new urologists, say to leave it alone. Last month for the first time in my life, I had pain on the RIGHT side, and within 12 hours passed a 2.5mm, reddish brown stone that weighed 0.0090. Analysis showed the stone to be 50/50 calcium oxalate monohydrate/dihydrate. I am not obese, exercise moderately, have normal blood labs, eat a largely vegetable/protein diet void of added sugars, salts or carbohydrates & drink only plain water & black, weakly brewed, unsweetened decaffeinated coffee. I get migraine AURAs without headache routinely, which lead me to think I may be in a perpetual state of dehydration. Thank you!
Hi Stewart, No one can know why you have formed stones in both kidneys unless testing is done properly. Here is my best offering about how to proceed. See if it works for you. Regards, Fred Coe
Very fascinating. I am a 71-year-old man, non-drinker, non-smoker with a 9.5mm lower pole non-obstructing nephrolith of LEFT kidney as seen on a recent CT scan. The stone has been there for many years without issue. Both my former and new urologists, say to leave it alone. Last month for the first time in my life, I had pain on the RIGHT side, and within 12 hours passed a 2.5mm, reddish brown stone that weighed 0.0090. Analysis showed the stone to be 50/50 calcium oxalate monohydrate/dihydrate. I am not obese, exercise moderately, have normal blood labs, eat a largely vegetable/protein diet void of added sugars, salts or carbohydrates & drink only plain water & black, weakly brewed, unsweetened decaffeinated coffee. I get migraine AURAs without headache routinely, which lead me to think I may be in a perpetual state of dehydration. Thank you!
Hi Stewart, No one can know why you have formed stones in both kidneys unless testing is done properly. Here is my best offering about how to proceed. See if it works for you. Regards, Fred Coe
My recent stone analysis showed calcium oxalate monohydrate 30% and hydroxyapatite crystal 70%. I am limiting my oxalate food intake to 50g per day and that level has drastically improved, but I can’t find information about addressing the hydroxyapatite crystal formation. Thank you for any suggestions you may offer!
Hi Linda, You are a calcium phosphate stone former and it is urine pH, citrate, and calcium that will most control new stones. Hydroxyapatite is calcium phosphate crystals like in bone. Regards, Fred Coe
My recent stone analysis showed calcium oxalate monohydrate 30% and hydroxyapatite crystal 70%. I am limiting my oxalate food intake to 50g per day and that level has drastically improved, but I can’t find information about addressing the hydroxyapatite crystal formation. Thank you for any suggestions you may offer!
Hi Linda, You are a calcium phosphate stone former and it is urine pH, citrate, and calcium that will most control new stones. Hydroxyapatite is calcium phosphate crystals like in bone. Regards, Fred Coe
– COMPOSITION:
CALCIUM OXALATE MONOHYDRATE – 30%. CALCIUM OXALATE DIHYDRATE – 60%. HYDROXYAPATITE – 10%.
Hi Rhonda, Your stone indicated a main risk for calcium phosphate crystallization. It is like common stones but with more complexity and risk for rapid growth and perhaps resistance to shock wave lithotripsy. The two links give a good introduction as to what you might want from your physicians. Regards, Fred Coe
– COMPOSITION:
CALCIUM OXALATE MONOHYDRATE – 30%. CALCIUM OXALATE DIHYDRATE – 60%. HYDROXYAPATITE – 10%.
My recent analysis (first stone, but 3 small still remaining in right kidney) returned 20% Calcium Oxalate Dihydrate, 60% Calcium Oxalate Monohydrate, and 20% Carbonate Apatite. My doctor only told me watch oxalate intake and drink more water (which I already felt I do quite a bit). Any suggestions regarding diet or other testing to request to help provide more insight is appreciated greatly!
Hi Chris, You form calcium oxalate stones and do not know why. The key is to find the causes and aim treatment at them. Here is my best overview of what to do and how. See if it works for you. Regards, Fred Coe
My recent analysis (first stone, but 3 small still remaining in right kidney) returned 20% Calcium Oxalate Dihydrate, 60% Calcium Oxalate Monohydrate, and 20% Carbonate Apatite. My doctor only told me watch oxalate intake and drink more water (which I already felt I do quite a bit). Any suggestions regarding diet or other testing to request to help provide more insight is appreciated greatly!
Hi Chris, You form calcium oxalate stones and do not know why. The key is to find the causes and aim treatment at them. Here is my best overview of what to do and how. See if it works for you. Regards, Fred Coe
Hi Gloria, given 35% dahlite (Calcium phosphate based, hyrroxyapate enriched with carbonate) you probably have a high urine pH, perhaps low citrate, probably high urine calcium. Crucial for you is a complete evaluation including 24 hour urine samples. Prevention is important as phosphate stones can grow a bit faster and larger than calcium oxalate stones. Regards, Fred Coe
Hi Gloria, given 35% dahlite (Calcium phosphate based, hyrroxyapate enriched with carbonate) you probably have a high urine pH, perhaps low citrate, probably high urine calcium. Crucial for you is a complete evaluation including 24 hour urine samples. Prevention is important as phosphate stones can grow a bit faster and larger than calcium oxalate stones. Regards, Fred Coe
Hi Dr. Coe, I recently passed a stone and I was able to capture it. The Stone analysis – Details is 50% Calcium oxalate dihydrate, 40% Calcium oxalate monohydrate and 10% Calcium phosphate (apatite). Is this a concern? Once in 2/3 weeks I get a serious back pain that last a day. Could this be a cause? What would you recommend to me going forward? Thanks!
Hi VIck, It is the common calcium oxalate stone and can recur. I would recommend a proper evaluation as to cause. Here is my best take on that. REgards, Fred Coe
My results for my kidney stone was 90% calculi oxalate monohydrate and 10% calculi oxalate dihydrate. I was just wondering what that means.
Hi Paige, that is the most common stone. Next steps toward prevention are in this article. Regards, Fred Coe
My results for my kidney stone was 90% calculi oxalate monohydrate and 10% calculi oxalate dihydrate. I was just wondering what that means.
Hi Paige, that is the most common stone. Next steps toward prevention are in this article. Regards, Fred Coe
I know I have two kidney stones currently hanging out in my system after passing one just over a year ago. When my PCP analyzed it, she just called it an oxalate stone, but I’m looking back at the results because I think I am passing another one, and they indicated it was 50% calcium oxalate monohydrate 50% ammonium acid urate. She told me not to worry about it, but this post makes me think I should have worried more about it…would love your thoughts!
Hi Mon, Ammonium acid urate generally occurs when urine pH is moderately high and urine ammonia higher than normal. Diarrhea and potassium depletion are the common causes. A problem is that stone analysis for ammonium acid urate KIDNEY STONE ANALYSIS: How Bad is It? might be in error, but in the studies I have reported that error was not particularly serious. Do you have one of the conditions I mentioned. Does your urine contain high ammonia and also a high pH? Regards, Fred Coe
My mother in law suffers with kidney stones constantly. Multiple surgeries and hospitalizations from resulting sepsis. She again has “multiple” stone in both kidneys. A previous urine catch showed: 95% hydroxyapatite 5% calcium oxalate monohydratel. What is causing her to constantly suffer from these stones? Is there diet changes she can make?
Hi Lisa, calcium phosphate stones are a big problem. This is a reasonable article focused on them and perhaps will be of some help. Regards, Fred Coe
I know I have two kidney stones currently hanging out in my system after passing one just over a year ago. When my PCP analyzed it, she just called it an oxalate stone, but I’m looking back at the results because I think I am passing another one, and they indicated it was 50% calcium oxalate monohydrate 50% ammonium acid urate. She told me not to worry about it, but this post makes me think I should have worried more about it…would love your thoughts!
Hi Mon, Ammonium acid urate generally occurs when urine pH is moderately high and urine ammonia higher than normal. Diarrhea and potassium depletion are the common causes. A problem is that stone analysis for ammonium acid urate KIDNEY STONE ANALYSIS: How Bad is It? might be in error, but in the studies I have reported that error was not particularly serious. Do you have one of the conditions I mentioned. Does your urine contain high ammonia and also a high pH? Regards, Fred Coe
My mother in law suffers with kidney stones constantly. Multiple surgeries and hospitalizations from resulting sepsis. She again has “multiple” stone in both kidneys. A previous urine catch showed: 95% hydroxyapatite 5% calcium oxalate monohydratel. What is causing her to constantly suffer from these stones? Is there diet changes she can make?
Hi Lisa, calcium phosphate stones are a big problem. This is a reasonable article focused on them and perhaps will be of some help. Regards, Fred Coe
Calculi composed primarily of:
30% calcium oxalate monohydrate, 20% calcium oxalate dihydrate, and
50% calcium phosphate (hydroxy- and carbonate- apatite).
Hi Elaine, You have a lot of phosphate in your stones, and this article is all about your situation. Regards, Fred Coe
Calculi composed primarily of:
30% calcium oxalate monohydrate, 20% calcium oxalate dihydrate, and
50% calcium phosphate (hydroxy- and carbonate- apatite).
Hi Elaine, You have a lot of phosphate in your stones, and this article is all about your situation. Regards, Fred Coe
My 24 hour urine test shows calcium 480 and normal is less than 250. And brushite 275 and normal is less than 200. I passed a 4mm stone with the help of Flomax. The urologist office lost the stone I gave them for analysis. I have a 2 mm stone in each kidney along with a group of crystals in one kidney. Neither the urologist or nephrologist have wanted to do more testing or treatment. Just drink water is their response to me. Can you recommend a kidney stone center near Tampa, Florida? If not, I was thinking going to a university hospital. Should I see an urologist or nephrologist? Thank you for your help.
Hi Wendy, There is a medical school stone center in Tampa. I would start there. Regards, Fred Coe
Thank you. I have an appointment this coming Monday at the stone center you recommended.. As my old urologist office lost the kidney stone I passed would the new urologist have an idea, from my 24 hour urine results, what kind of stones my kidneys make? The only values on the report that were elevated are calcium and brushite.
Hi Wendy, Perhaps, but it would be guessing. Fred
My 24 hour urine test shows calcium 480 and normal is less than 250. And brushite 275 and normal is less than 200. I passed a 4mm stone with the help of Flomax. The urologist office lost the stone I gave them for analysis. I have a 2 mm stone in each kidney along with a group of crystals in one kidney. Neither the urologist or nephrologist have wanted to do more testing or treatment. Just drink water is their response to me. Can you recommend a kidney stone center near Tampa, Florida? If not, I was thinking going to a university hospital. Should I see an urologist or nephrologist? Thank you for your help.
Hi Wendy, There is a medical school stone center in Tampa. I would start there. Regards, Fred Coe
Thank you. I have an appointment this coming Monday at the stone center you recommended.. As my old urologist office lost the kidney stone I passed would the new urologist have an idea, from my 24 hour urine results, what kind of stones my kidneys make? The only values on the report that were elevated are calcium and brushite.
Hi Wendy, Perhaps, but it would be guessing. Fred
I had my appointment at the stone center in Tampa which you recommended. They advised the same diet: low sodium, adequate calcium, etc. which you advise. I was prescribed 25 mg chlorthalidone daily with dinner. My question and concern: I have controlled insulin resistance from long term polycystic ovarian syndrome. I have read reports of increased blood sugar from chlorthalidone. Is this true? Also I was wondering if I should have been started at 12.5 mg as it is causing gastritis? No mention of repeat 24 hour urine as a follow up. How long should I wait for a follow up 24 hour urine to see if the drug helps with my high calcium and brushite levels? Thank you. PS They wanted to know more about you and your expertise so I shared this site with them.
Hi Wendy, I was not there and hate second guessing. Indeed a lower dose is less likely to raise blood glucose, and one does need 24 hour urine followup with your personal physicians can easily order for you. I would wait at least 6 weeks and be sure to lower diet sodium as much as possible so the drug is most effective. Regards, Fred Coe
I am 33 years old I have 3.7 cm calcium oxalate stone I go through PCNL procedure only a smaller amount has broken now stent has placed in kidney for next session.
Hello Dr, I am sorry for the delay. I hope by now the stone has been removed. It was a very large stone, and I wonder if it was calcium oxalate or perhaps something else. Let me know and I promise to answer more promptly. Regards, Fred Coe
Hello Dr. Coe: I am “new” to the world of kidney stones. In July 2022, without any pain symptoms, but fairly frequent UTIs, I was referred to a urologist in the Chicago suburbs. Turns out, I had a 20mm stone located in the lower lobe of my left kidney! I opted for lithotripsies (3 to date). The procedures were fairly successful and I was able to collect a lot of stone fragments (again without pain, thank goodness!). Lab analysis indicates the composition as : 50% Calcium Oxalate Dihydrate (Weddellite) and 50% Carbonate Apatite. My urologist said we could wait a few months since most of the stone looked like it was broken up and passing. Feb 2023: I just went back to have the KUB x-ray to see the progression and, unfortunately, the small remainder of the 1st stone was still present and 3 more medium stones have been created (still all in the lower lobe). What now?! P.S. Thank you for all you do to share information and provide knowledge! -Nancy
Hi Nancy, I am very sorry for such a delay. The site has been under reconstruction and some messages got buried. You are forming calcium phosphate stones which grow back rapidly and pose their own special problems. Prevention is often difficult and depends a lot on the urine chemistries that are promoting the stones. Though detailed your note does not contain those values so I have little to add right now. Regards, Fred Coe