CoeTie4At the end of it all, the science, the medical visits, the surgeries, what we really want is to prevent new stones. That is the main goal. Modern surgery is a blessing for those with stones. But no surgery is far better than even the most skilled and effective surgery.

Prevention of stones is orderly and occurs only over time.

Here is how to do it.

This article is designed to go with my other one which tells how to organize your medical visits so as to achieve these steps. 

What is the Science of the Five Steps?

Stones are made of crystals.

Supersaturation drives crystal formation and growth – this is a physical law that must always apply.

Supersaturation measurements are widely available from commercial vendors.

Because people who are actively forming stones are forming crystals their supersaturations are too high – crystals are forming – with respect to those crystals.

Lower the relevant supersaturations and you must lower formation and growth of those crystals in their stones.

With respect to the most common stones, calcium oxalate and calcium phosphate, and uric acid, supersaturation in urine depends mainly on volume, calcium, oxalate, citrate, and pH. You can lower supersaturation by altering any or all of these in a given person and so far as crystals are concerned the effects are much the same. 

1. Know the Stone Crystals

Stones are made of crystals: No crystals no stones. Prevention is prevention of crystals.

Analyze Stones

The proper way to know the crystals is analysis of stones and their fragments. Stone analysis is not expensive. If imperfect, it is the best we have, so use the service liberally. Stone crystals can change, and therefore prevention can need to change direction. There is no reason to discard a stone without analysis just because we think we know the answer.

Uric acid stones are remarkably easy to treat by raising urine pH and require little more discussion.

Cystine stones arise from hereditary kidney transport disorders and require special management.

Struvite stones arise from infection and require special combined surgical medical management.

Drug stones, ammonium acid urate stones, and rare stones – eg. 2,8 dihydroxyadenine stones require special management.

The vast proportion of kidney stones are calcium oxalate and calcium phosphates and uric acid, and this article refers mainly to them.

Guess if You Have To

Red or orange stones probably contain uric acid. Likewise, stones that do not show up on simple abdominal flat plate x rays are probably uric acid. These are easy to prevent, and recurrences are unnecessary.

Allow me to elaborate on this. Pure uric acid stones are almost all due to an excessively acid urine pH, and will stop if you raise that pH. Potassium citrate tablets, 10 mEq size, 2 twice daily is almost always enough. Sometimes it takes 2 tabs 3 times a day. Crystal light lemonade has in one liter about the same amount of alkali as two of the tablets. I could say that there is little excuse for another uric acid stone.

If stones contain uric acid and other crystals, those other crystals need to be dealt with on their own. They may not respond to higher urine pH, and could be worsened.

Yellow stones are probably cystine, and due to cystinuria, a complex disease with its own special treatments. Because almost all kidney stone panels include a cystine screening test, cystinuria is almost never missed. A positive test, however, can reflect cystine trait and the stones can be something else. So it is the negative test that is fully informative.

Small black stones are probably calcium oxalate, and large very homogeneous hard stones are probably brushite. But one cannot be sure.

Big stones that fill up the interior of the kidney are usually cystinestruvite – from infection, or calcium phosphates from alkaline urine and hypercalciuria.

But guessing is not a good way to achieve prevention. Find out whenever possible what crystals you are trying to prevent. Any stone fragment can be analysed. Never pass up an chance to be sure.

2. Obtain Proper Blood and 24 Hour Urine Measurements

I prefer two 24 hour urine kidney stone risk panels as a minimum along with at least one set of fasting blood measurements.

Screen for Systemic Diseases

Here is a table of systemic causes any physician can follow using the blood and 24 hour urine testing. This is not something a patient can do anything about except see that it is accomplished.

Revised Table for Evaluation for Systemic Causes of Stones

The bowel diseases that cause enteric hyperoxaluria – small bowel resection, malabsorption, are usually obvious, as are ileostomy and bariatric surgery.

Medullary sponge kidney and nephrocalcinosis are complicating features physicians need to deal with. Medullary sponge kidneys actually form tiny micro crystals in their dilated ducts. Whether these grow to become clinically important is not clear.

Nephrocalcinosis simply means many crystals are present on x ray images. During ureteroscopy these crystal deposits can be sorted out into real stones and plugs within the terminal ducts of the kidneys. Pain without obstruction is widely described in both of these conditions which complicates management.

Measure Urine Supersaturations of the Stone Crystals

Standard 24 hour urine kidney stone risk panels give supersaturations along with the urine chemistries that control those supersaturations. These are the keys to prevention. Supersaturations control crystallization and can be measured reliably in people. If crystals are being formed the supersaturation is too high and we need to lower it.

Read Your 24 Hour Urine Reports

Your physician will take care of you but a prepared and educated patient can make that care vastly more effective and reliable.

You can understand your 24 hour urine tests and follow along with your physician during your visits and when treatment has been introduced and your urine chemistries change as a result. The details of interest are different for calcium stones and uric acid stones, so I have put them in two separate articles. Do not be put off by all the numbers. Follow the articles with your test panel in hand and you will find things are not so difficult.

Stone prevention is long term and involves changes in diet and behavior and, often, medication use. If you can read your own report you will have a first hand sense of why your treatments are good for prevention and whether your treatments have achieved what they were designed to achieve.

3. Lower By Half the Supersaturations for the Crystals in Stones

There is no one way to reduce supersaturations. Every patient will have a characteristic pattern of abnormalities and supersaturation can be lowered by changing any number of those abnormalities present. Below is my general strategy, but it may not apply to you. If your urine volume is already very high, for example, to raise it would be silly. So consider my ‘strategy’ a general set of rules, easily modified to fit the individual situation.

Raise Urine Volume as High as is Practical

Above 2.5 liters daily is ideal. The site is very rich in advice for fluid treatments. How to drink more. How to get variety. How to avoid low flow periods. Being without cost or risk, fluids are always my first choice.

Reverse Urine Abnormalities Raising Supersaturations for the Crystals in Stones

urine calcium oxalate volume and citrate vs risk of stones from Curhan plotted with identical risk axesIdentify the factors in the 24 hour urine beside volume that are raising supersaturations for the crystals in stones, and act so as to reverse them toward normal. Common ones are high urine calcium, high urine oxalate from diet, low urine citrate, and low urine pH – for uric acid stones. High pH is a risk factor for calcium phosphate stones but one cannot lower urine pH under most circumstances.

Bang For the Buck

A vulgar phrase, if you think about it. Here are the relative risks of becoming a stone former in the three cohorts of nurses (red) and physicians (males, blue) Dr. Gary Curhan followed. You might say relative to what. For each risk factor it is different: Calcium – less than 100 mg/day; Oxalate – less than 20 mg/day; Citrate – less than 300 mg/day; Volume, less than 1 liter.

The average relative risk is at the end of the crosshatched bars. The ends of the solid bars are the 95th percentiles. When the solid bars are above one risk is certainly present, so you can see the safe ranges for calcium, oxalate, citrate, and volume. Because the plots all have the same risk ranges you can compare these four risk factors. Calcium has the widest  effect range. Oxalate is next and increases risk at even 25 mg/day. Citrate causes risk only when below 400 mg/day, and volumes above 2 – 2.24 liters lower all three cohorts into a low risk range.

Although urine volume confers relative risk equivalent to high urine calcium and oxalate only when below 1.25 liters daily (see graph at left), one always wants to raise it as much as is possible because such treatment is without risk or cost. Above 2.25 liters daily is ideal. The site is very rich in advice for fluid treatments. How to drink more. How to get variety. How to avoid low flow periods.

Obtain New 24 Hour Urines to be Sure Supersaturations Have Fallen

There is no point to changing diets or medications without proper follow up to determine if what was done had the desired effects. Six weeks is a good time for the first follow up measurement. Continue measurements until the supersaturation goals have been achieved.

4. Obtain more 24 Hour Urines if New Stones Continue

Crystals follow physical laws and supersaturation is what drives them to form and grow. Continued stones with reduced supersaturations means either supersaturations need to be lower, the 24 hour samples are not being taken on representative days, or the days themselves have periods of low urine flow or other breaks in treatment.

Crystals do not sleep nor do they make mistakes. Any chances they get, they use.

Physicians are trained to ferret out the details of a patient’s history that matter here. It is my main clinical expertise. 

Patients are not trained but they are the ones sitting up close at the 50 yard line. So they know more than anyone else. They just may not know what is important for stone prevention.

5. Follow Up Every Year Thereafter Even If Free of New Stones

OH, you might say, those urine measurements cost money.

They do, hundreds of dollars for each one.

The merest surgery can cost near to or even above ten thousand dollars when you consider the total of medical, operating room, anesthesia, and pre and postoperative imaging costs, and the inevitable emergency room visits that provoke the surgery in the first place. This is not to mention lost time from work.

And, did I speak about pain, misery, infections?

It it time for blunt talk. Lab measurements are the compass and altimeter. Flying blind is silly.

A Good Way to Get All This Done

You cannot do the five steps alone, your physician is crucial. He or she cannot do them either; you are crucial. In case you missed it, here is my view on how a patient and physician can best partner for stone prevention

That’s It

This site is far from complete but it already has a lot of what one needs to carry out these five critical steps. Do them and new stones will cease altogether or at least greatly reduce in frequency. If it does not work, one or more of the steps need correcting. After nearly 45 years preventing stones, I have become bold enough to say this, and mean it.

Good Luck, Fred Coe


  1. deborah

    Hello… I have a double collective system on my left kidney. there are two tubes from my kidney that join together just above the bladder, forming a Y. About 10 years ago I had kidney stones, but could not pass them because they got stuck at the join. I had to have them surgically removed. It was horrible, My urologist put a tube into my back, to my kidney, and I had a bag on it. He needed to create a pathway to the kidney for the surgery. I wore that thing for 2 weeks. He went in and broke up the stones and removed them. Now, about 10 years later I just learned that I have another stone in the same kidney. The stones were calcium oxylate. I am 67 yo and devastated by the news. I can’t take going through that again. Please tell me there are less invasive procedures now. I can’t pass stones because of my double collective system. I am terrified. And does eating nuts really cause kidney stones?

    • Fredric Coe, MD

      Hi Deborah, I understand your worries. The article is a great plan for evaluation and prevention. As for the surgery I would think a modern flexible ureteroscope should navigate the join with a bit of guile. I gather the join is just above the bladder, but that seems odd; perhaps you mean just below the renal pelvis. In any event, instruments have improved massively since your prior procedure and I am hopeful your surgeon will not have to do so much this time. But prevention is orderly – follow the article. Best, Fred Coe

  2. Bob

    I posted my case of bladder stones here and asked for advice yesterday. But my post has been deleted without explanation.


  3. Bob

    Corrections: In the previous post, the length of my bladder stone should be 2 cm, not 2 mm.

  4. Bob

    Hello Dr. Coe,

    Thank you for the article. I had bladder stones removed in March. The stones consist of 15% calcium oxalate dihydrate, 70% calcium oxalate monohydrate, 15% carbonate apatite, stone weights 0.287g. The length is about 2mm. My kidney shows no stones.

    The subsequent 24-hour urine tests (w/o creatinine) shows:
    oxalic acid: 76 mg/24 h ref: 3.6-38
    magnesium: 72 mg/24 h ref: 28-180
    calcium: 117 mg/ 24 h ref: 55-300
    uric acid: 632 mg/24 h ref: 120-820
    total voume: 2296 mL

    24-hour urine tests (w/o creatinine) shows:
    citric acid: 647 mg/24 h ref: 100-1300
    citric acid: 357 mg/g creat ref: 60-660
    vreatinine: 1.81 g/24 h 0.63-2.5
    total volume: 1915 mL

    I used to eat high oxalate food a lot, such as yam, almonds, pecans, berries…
    Now I changed my diets to lower oxalate intake.
    Since I have no kidney stones, are there any other tests I should take to identify the cause of my bladder stones? Any other measures shall I take to prevent it?

    Thank you so much for your time and help!

  5. Ness

    Hello I am hoping you can help me with your expertise knowledge but not for myself but for my companion fur baby, female dog. She was diagnosed with a stone in her ureter measuring 6mm then on second ultrasound it measured 10mm. She has a bacterial infection unidentified at the moment, and passed mucous and blood clots in her urine for 2 days. This has now cleared. Her alkaline phosphatase in her blood test was high. Measuring 220 U/L which is outside the normal range (1-120). Anion gap was also high 29mmol/l just slightly over normal range (15-25). I am wondering if with this information we could know what kind of stone she has so I can adjust her diet. We are giving her lots of fluids, and she is taking Prazosin. Calcium was normal 2.53mmol/l (2-2.8 is normal). Thank you.

    • Fredric Coe, MD

      Hi Ness, Veterinary medicine is complex, specialized, and far out of my league. The animals – apart from humans – are off limits because I just don’t know enough to be helpful. You need the right professional here, and I gather you have one. The kind of stone cannot be deduced from what you have provided, and the use of stone analysis in dogs lies outside my range of professional knowledge. Sorry, Fred

  6. Adele

    Hello Dr Coe. I have been been having problems with calcium oxalate kidney stones for the past eleven years. It was established I had hypercalciuria and then three years ago it was discovered I suffered from Hyperparathyriodism. I had surgery (removal of three of the parathyroids) to correct the problem just over two years ago. My blood calcium levels have returned to normal but I am still creating stones. My urologist is not particularly interested as to why I am continuing to create stones his only advice was to keep hydrated. I am trying my best to research how to manage my condition and how to minimise / prevent the creation of the stones. Recent scans have confirmed that new stones are forming which puts beyond question that the correction of the hyperparathyroidism has not resolved the issue of the stones. What approach do I need to take to at least try and find why this is continuing. Many thanks in advance for any pointers you can give me in trying to steer my doctors in to at least attempting to determine what is now happening.

  7. Joanna

    I recently had a scan as part of a general check up,, and was told that I have one kidney stone, 7mm. From what I have read about the formation of kidney stones, I believe that it possibly developed because until a few months ago I was a keen coffee drinker and also used to eat a lot of cheese. I have changed my diet over the past two months, eating many more alkaline foods. I am due to have another scan in a week’s time to see what is happening with the stone. The doctor has simply suggested that I should drink more, but I already drink about 2 -3 liters each day (water or herbal teas). Do you know if there is anything else that I can safely do in the hope of dissolving the stone or should I wait until I have had the scan and discussed the results with the doctor? I am not in any pain, and it seems that my blood & urine results have all come back normal. Thank you for your help, kind regards, Joanna

  8. Melissa DiLella

    Hi Dr. Coe,
    I have been struggling with kidney stones since September 2016 I have passed one 5mm stone and had a Right ureteroscopy with laser lithiotripsy on 3/10/17. My stones have been analyzed twice here are the results: Calculi composed primarily of:
    80% calcium oxalate monohydrate, and
    20% calcium phosphate (hydroxy- and carbonate- apatite).
    INTERPRETIVE INFORMATION: Calculi (Stone) analysis
    Calculi are the products of physiological processes that yield
    crystalline compounds in a matrix of biological compounds and
    blood. Matrix components are not reported. The clinically
    significant crystalline components identified in calculi specimens
    are reported. Gross description may not be consistent with
    composition determined by FTIR analysis.

    the stone from November 18 2016 results are : Calculi composed primarily of
    calcium phosphate (hydroxy- and carbonate- apatite).
    INTERPRETIVE INFORMATION: Calculi (Stone) analysis
    Calculi are the products of physiological processes that yield
    crystalline compounds in a matrix of biological compounds and
    blood. Matrix components are not reported. The clinically
    significant crystalline components identified in calculi specimens
    are reported. Gross description may not be consistent with
    composition determined by FTIR analysis.
    Performed by ARUP Laboratories,

    I still have two stones in my left kidney and 6 in my right. I am becoming very frustrated. My urologist is telling me that all I can really do is decrease animal protein and sodium and increase fruit and veggies. I have to believe there is more that can be done to prevent any more stones form forming. I hope you can help.

    • Fredric Coe, MD

      Hi Melissa, You form stones composed of calcium oxalate and calcium phosphate, and you are reading the Five Steps article. What you need to do is finish all of the steps. You know the stone composition. Your physician needs to exclude systemic diseases – there is a chart in the article for him/her. You need 24 hour urine testing and then directed treatment. I would suggest you just follow the outline you are reading. Regards, Fred Coe

  9. WadeW

    Hello Dr. Coe,
    This has been a truly helpful site for me ever since last year when I realized that I am a stone-former.
    A bit about myself: I am 36-year old South-asian male, 5 feet 6 inches and 70 kilogrammes. From where I am, we luckily get just three months of winter and the rest of the time it is extremely hot. The last few years, our summer months suffered with temperatures at 42 degrees celsius.
    I have always had nearly 2.5 to 3 litres of water. But over the past six years, I have noticed that my urine colour becomes yellow if I do not pee within a matter of three to four hours. Earlier, I could hold on to my pee for five to six hours and the colour was usually the same: colourless.
    After some summer nights, my urine even became honey yellow.
    So, I had been to several doctors, who gave me urinalysis and other tests. They came out normal and they asked me to quit worrying.
    I often noticed little black specks in my urine. Very small like pepper grains. I had tried to ascertain whether these were blood clots. But fortunately, they usually flipped or swept away intact when I dropped water on them. I was then around 74 kilogrammes.
    Cut to last year in March, I had a bout of hematuria. I was extremely scared. But after having a litre of water, the urine went back to normal colour of light yellow during the next bathroom break.
    I went to the doctor. He gave me a bunch of tests. Everything came back normal.
    I began to walk and dropped around 6 kilogrammes within the next four months. But again in April, a month after the first episode, I had gross hematuria again: this time for three days.
    The doctors took this seriously now. Gave me KUB Ultrasound, Xrays, phase contrast microscopy and other things. Everything came normal. They did not find any stones. and the phase contrast found that the blood was from the Lower urinary tract.
    I used to feel like something was pressing down on my left testicle. It was so bad that I could not even sleep at night.
    I was more or less certain that I have bladder cancer. But three urologists and a nephrologist assured me that I dont, based on the USG, Xrays and other test findings.
    The RBC in my urine continued over the next one and a half months but it gradually decreased. It went from RBC ‘numerous’ to ‘0-1’ during repeated urinalysis over intervals of a week or so.Finally it stopped around July. It was there from the beginning of May till July.
    Then around July, I began to feel pain near my abdomen. Like a steel button was being pressed from the inside. I went to the doctors. They gave me sleeping pills. I did not take them.
    Finally around the first week of August, around morning, I passed a more than 3 mm stone with really sharp edges. I read your posts and wanted to have the stone analyzed. My urologists did not feel the need of it.
    I still often felt some pain for the next few weeks. I went back to ask whether there could be more stones. I also passed a flat oval shaped black thing that was intact and did not seem like a blood clot. Told the uros. They told me that this is probably another stone element and dismissed me.
    Having gone through all these problems, I am now trying to deal with the stone problems by myself. I have stopped having green spinach, chocolates, coffee, black tea and additional sugar and salt with my food and drink (I regularly used to take a pinch of salt with my rice during lunch and dinner).
    I am regularly walking around 3 to 4 kilometres now.
    I would have actually come to you if you were anywhere near my country. Since I cannot, I hope you wont mind me ask the following questions:
    1) I am currently drinking 3.5 to 4 litres of water per day. Can I have mint flavoured green tea as a part of this? Will this help in preventing stones?
    2) Should I decrease the amount of chicken and beef that I have with my meals?
    3) Is oat better for kidney stone prevention over rice as staple food with curry and vegetables?
    I still often spot one or two black specks in my urine. Help from you will be greatly appreciated.
    Thanks in advance.

  10. pat hallock

    my 92 year old mother has a 13 m kidney stone and has been taking potassium citrate for the past month . she is scheduled for a laser procedure on march 28th. she has been cleared for the procedure by a cardiologist. is there any other options for eliminating this size stone, thanks, pat

    • Fredric Coe, MD

      Hi Pat, Surgical decisions are very much in the hands of the surgeon. Ureteroscopy with laser disruption is ideal. I know of no better way. Regards, Fred Coe

  11. Peggy Stein

    Hi, I have had uric acid stones and just moved into a house with very hard water. Do you have a recommendation about water softeners?

    • Fredric Coe, MD

      Hi Jenny, Nothing could matter less. Uric acid stones are due to unduly acid urine and cured permanently with enough alkali to raise the urine alkalinity. I am sure your physician already this and you will not need to have another stone. Regards, Fred Coe

  12. Jo kolstee

    I have a nightmare life going on here! So hoping that you can lead me in the right direction. In a year and a half I have had four surgeries for kidney stones in both kidneys. 10/5/15, 3/23/16, 6/23/16 and 2/16/17. The urologist identified the stones as brushite. I also had a nephrolithotomy with the 3/23/16 surgery and one stone measured 23 cm and one two days ago was 11 cm. Each surgery the urologist says he breaks up and removes as many as he can but that I have over 100 stones affecting both kidneys. I have learned not to go to the ER as they can only tell me to up my pain medication and see my urologist. On my last visit to the ER I was given Toradol. That was a life saver but I have only had to resort to that twice. About four months ago I saw a nephrologist but was disappointed in that he also only offered crisis management. He did tell me to up my water intake and cut down on oxalates and phosphorus. Funny in a way because I do know exactly what I take in as I have had a feeding tube in place due to the effects of chemo and radiation for right tonsil cancer. I have been on a strictly limited liquid formula diet for two years. I had a 24 hour urine collection test done on 8/11/16 That showed my urine volume was extremely low at 0.94 and I needed to consume more water which I have done through the feeding tube. Hyporoxaluria is circled on the report. Having just had surgery two days ago I am once again dealing with the painful stents. I have an appointment with the urologist to have the stents removed in three weeks. I also have an appointment with the nephrologist at the end of the month. Both doctors are from another country and extremely hard to understand. I think I could get the gist of what they say but neither one is forthcoming with any suggestions as to what I could/need to do. Please let me know what your thoughts are as to the direction I should take. I fear my body can’t take much more of this !

    • Fredric Coe, MD

      Hi Jo, Your stones are calcium phosphate, so the high oxalate is not material. THe low volume is crucial and needs correction. You cannot lower urine phosphate significantly unless it is artificially high from your tube feeds. I suggest you review your 24 hour urine lab findings – here is some help – and get advice from the tube feed experts about changes. Brushite stones are hard, grow rapidly and do need very aggressive prevention, as you have guessed. Regards, Fred Coe

      • Jo kolstee

        I am so confused ! After having the surgery on Feb. 16, 2017 And having stents placed in both kidneys by the urologist I saw the nephrologist on Feb. 28th. He was stumped by my telling him my stones were Brushite. He said he had not seen a case in many years that were identified as Brushite. He said he would study Brushite and get back to me. Mind you he had my medical history in front of him including the 24 hour urine collection results. He of course stressed the importance of increasing the water intake through the G-tube which I have done. But, that I had no diet restrictions. Four days later I had a KUB x-Ray done prior to seeing the urologist on March 8th. The urologist made the decision to leave the stents in place until March 14th but to schedule yet another surgery soon. This time a nephrolithotomy as an inpatient again. Today I received a follow up call from the nephrologist saying the term Brushite is just an old term not used anymore and that I have calcium sulfate stones. (Verses your term calcium phosphate). He said I should go back on the diet of restricted oxalates, phosphorus and now uric acid also. As I am still tube feeding I have cut the amount of 2Cal formula in half and replaced it with low oxalates and phosphorus liquids. I am going right now to your suggestion of studying my lab results hoping for direction on all of this. I am desperately trying to figure out what to do to limit the surgeries as I am in pretty poor health dealing with the aftermath of chemo and radiation and certainly did not bounce back from the last surgery on Feb. 16th. I am now down to 82 pounds vs 138 pre chemo and radiation. I am only 4ft 9 inches tall so not a complete skeleton but close. I am fighting as hard as I can to get calories and hydration through the tube each day. In trying to study each label the confusion is great as it seems each different classification has different steps to follow to minimize the formations. So, I feel as though I am flying blind here and don’t know which way to turn. I so value your opinion as to what I should do to improve my situation. I sincerely thank you.

        • Fredric Coe, MD

          Hi Jo, Brushite stones are not rare, but they do pose special problems being hard to break. If your physician indeed meant to say that brushite – the name of calcium monohydrogen phosphate – is no longer used, then he is not correct. If your stones are indeed calcium sulfate they are rare and I have no experience with such. Such a sulfate stone would have no relationship to diet oxalate or phosphate or uric acid. A brief search of PubMed for calcium sulfate and stones yielded no publications. Brushite stones usually arise from high urine calcium and urine pH, so treatment aims to raise volume and lower calcium losses. Given your serious medical issues and the strange kind of stone, consultation with an expert in stone disease – at a university preferably – would seem urgent. Regards, Fred Coe

  13. mrs johns

    having been a patient from 1993 and have not had a recurrence/stone growth enlargement according to cat scan while in hospital (unrelated medical issue 2012) and paying attention to salt/sodium intake,now but saw no mention here of the genetic issue for those carrying both mthfr gene variants 677/1298 (compound heterozygous diagnoosed 2013) and how the detox pathways/elimination are affected severely not to mention other body systems affected. understand doc Ben Lynch is an expert in this specific biochemistry………but would like to know about a genetic component re stones, excess calcium, etc….

    • Fredric Coe, MD

      Hi, I do not know of any relationship between this well known folate pathway mutation and kidney stones. High urine calcium is familial, but the genes are not yet determined. Regards, Fred Coe

  14. Jolene shannon

    I enjoyed the Information here! I was diagnosed with MSK in 2000 during my pregnancy with my oldest daughter. I passed several stones that apparently had an easier time coming out with the dilated ureters from pregnancy. I have had several stents, lithotripsy, and scopes over the years with on and off problems. In 2010, I gave birth to my youngest daughter and had a hard time because of kidney issues. I had several stones that got caught, tore my right ureter, and they ended up delivering me 6 weeks early because of the issues. She was healthy but I have had issues ever since with hematuria and renal colic. I ALWAYS have hematuria. My nephrologist has me on HCTZ and drinking lots of water, low sodium diet, but my urine never clears up. I often have contraction like pains in my right kidney, and I am worried it will never get better. Any further thoughts? I just did the 24 hour urine which I do often, calcium oxolate stones is what they always are. A recent CT without contrast said I didn’t have any obstructing stones visible at the moment. I appreciate the information. This disease is a painful one for sure.

    • Fredric Coe, MD

      Hi Jolene, I am not clear about your situation. Is it that the stones you pass or produce have been analysed and are calcium oxalate or are you saying the 24 hour urines suggest they are calcium oxalate. I will assume the former – stones have been analysed and are calcium oxalate. Since you read the five steps article, what was indeed found in the urine? Here is an article to help you understand your own results – see where you fit. That you continue to have pain and unclear urine suggests crystals are forming and things have not been fully treated so far. Regards, Fred Coe

  15. cindy

    Hi Dr Coe
    I have been having recurrent kidney stones and my first one in 2012 was treated with a lithotripsy with the resulting lab results:
    color- brown
    composition- SPRCS
    ca oxalate dehydrate- 05
    ca oxalate monohydr- 35
    calcium phosphate- 60
    I have had 2 more lithotripsy procedures since then about 2 years ago. Recently my blood pressure has been high 150/110 and I am on 2 B\P meds that are not effective. Could stone formation be causing my problem as my Dr states I may need stents. Is there something I can do to help this situation out? Thank you

    • Fredric Coe, MD

      Hi Cindy, You are forming predominantly calcium phosphate stones. The usual cause is high urine calcium and pH – too alkaline; treatment is usually as for all idiopathic calcium stone formers – no systemic disease identified. The marked hypertension may be a separate matter, and surely you should be treated. The very low sodium diet that is effective in lowering urine calcium will help to lower blood pressure. If you need stents, is that because of obstruction? If so, that is certainly a very serious matter; I cannot comment having no real information about this in you. Regards, Fred Coe

      • cindy

        Thank you for your response. Had follow up MD appointment and no occlusions in arteries to kidneys. However there is again a 9mm stone in my left kidney and no obstructions. So I am looking at your links to try to get this resolved. I never add salt to my foods but probably get too much from processed foods I suspect. Greatful for your knowledge thanks cc

        • Hannah

          Cindy, I am also an idiopathic calcium stone former. If you can go see Dr. Coe, I would highly recommend it. It is worth the flight (if that’s necessary). I had some very large stones and dozens of small ones, and with Dr. Coe’s help, I have been stone free for the last year. Also, find a VERY GOOD urologist that is really knowledgeable about stones. It made a huge difference for me. Lithotripsy caused me nothing but more problems.

  16. Julia

    Forgot to mention I am a nurse and as such am able to test my urine Ph, is there an ideal or not.
    Thanks again julia

  17. Margo Cooper

    I passed at least 1 stone Thursday night after sweating in the hot Texas sun all afternoon on Wednesday. I am 64 and had my first stone in my 30’s and have never gone to a doctor about it–but I started running a fevor and felt trauma over my whole body so called my doctor and got an antibiotic -still not up and around yet but will be insisting now to get my urine checked. Thank you! Lots of Google questions brought me to this site.

    • Fredric Coe, MD

      Hi Margo, Perhaps you have an infection from the obstruction from the stone. I am sure your physicians will treat that successfully. You should indeed figure out the cause. The plan you are reading is my favorite.
      Regards, Fred Coe

  18. Regina Leopold

    This is good information. I am about to see a new urologist in a few weeks. After having suffered with multiple bouts of stones over the last several years, I am no closer to an answer. The last one was just six months ago and I mentioned to the doctor at my follow up that my mother had kidney issues (and needed one removed) and maybe this was something passed on. He just shrugged and said he didn’t know and sent me on my way. I’ve NEVER had a physician actually try to figure out why I’m getting so many stones much less do a 24 hour test, they just remove them, give me the oxalate list, and send me home. I need answers!

  19. Tom

    Great site . . . just found it and will be reading up. I’ve had 2 episodes with stones. The first in 2002 when I was suddenly floored by pain. A trip to the ER determined it was a stone and I passed it a couple days later. Took it to my Dr and he kind of shrugged his shoulders and said, “yep . . . well, drink more water.” Not knowing any better, I went on my way. My last one came in 2008 and I knew exactly what it was. This time I got wise and saw my dad’s urologist . . . they gave me the strainer and when I caught it, they analyzed it. Calcium oxalate. They also did blood work and the 24 hour collection. With that, they gave me the information on going low oxalate and recommended increasing water and citrate consumption–and also recommended having a little milk or cheese with anything higher in oxalate that I ate.

    So far, so good. Hopefully I can avoid another for awhile . . . although it sounds like I am prone to getting them and it’s more a matter of trying to mitigate the risk & frequency? Anyway . . . I can’t stress enough how important it is to get the analysis done when you have one. If I had known enough to ask the right questions after the first stone, I possibly could have avoided the second or made it take longer to happen. At the time I had the second, I was on a ketogenic diet and eating a huge amount of almonds (cocoa roast, no less), peanut butter and spinach–along with chocolate flavored protein powder for weight lifting. Yeah . . . not good . . about the worst thing I could have been doing I later discovered.

    Thanks so much for providing such great info to folks like me.

    • Fredric Coe, MD

      Hi Tom, Thanks for the comment, and that you like the site. Even though there were reasons and you are stone free, consider checking things out according to a plan – so nothing is passed by. Here is a plan. Regards, Fred Coe

  20. E mair

    Im suffering now for aweek with a 3 mm kidney stone ive been drinking loads of water taking all the tablets the hosp has gave me im still in pain what else can i do

    • Fredric Coe, MD

      Hi E mair – Sorry if I have the name wrong! If your stone is not passing all this time, perhaps your physician would like to remove it. Also be sure it is not obstructing the kidney. Sounds like the limits are being reached. Pain pills go only so far. Regards, Fred Coe

  21. Michelle Groleu

    Hello Dr. Coe,
    You mention lemonade as helpful. I have been mixing a couple tablespoons of pure lemon juice with a tablespoon of water and drinking this at least once a day….up to three times a day. Will this help prevent the formation of calcium oxalate stones or of stones in general?
    Thanks for taking the time to let us know.

    • Fredric Coe, MD

      Hi Mike, The approach in the article is more comprehensive than this – if you followed it did you have a low urine citrate? If so perhaps the lemon juice is a good idea but it would hardly be enough. Followup urine testing would let you know. If you did not have a low citrate, but perhaps a high urine calcium or oxalate it would be possibly irrelevant. Likewise your stone type is important – was it calcium oxalate, calcium phosphate, both? Regards, Fred Coe

  22. Lisa M Viviano

    My kidney stones started because of parathryoid cancer. Post op I started to feel better than the cancer returned. Unusual, yes. I had another surgery and am on Natpara because of hypocalcemia. I’m still plagued with kidney stones after 18 months. I’ve altered my diet to help minimize oxalate, but am still in daily misery. If there any explanation as to why even with low serum calcium for 18 months I still have stones? I’ve been on high doses or calcium supplements which I’m now titrating down with the Natpara. Should I finally see some relief? Thank you.

    • Fredric Coe, MD

      Hi Lisa, Did you mean cancer or adenoma? Either way it seems you have hypoparathyroidism and are being treated with parathyroid hormone. I imagine the problem is with your urine and you need 24 hour urine testing to figure our your 24 hour urine calcium losses. Perhaps they are very high. Oxalate is not likely to be the big issue here. High doses of calcium in the presence of inadequate PTH treatment could result in massively high urine calcium and stones. Let us know, Regards, Fred Coe

  23. Gina Hamby

    Hi Dr. Cole,

    I have MSK in my right kidney and two large uric stones over 9mm in that same kidney. I have seen blood in my urine now for over a month and they did a Urine/bladder cytology because my urine cells were abnormal. The bladder is fine but the urine was abnormal. They put me on potassium citrate crystals 3,300 mg daily to dissolve these stones. My question is can that much potassium citate actually dissolve uric stones that large? Is there danger taking that much well I feel kind a sick to my stomach. Do I need to worry about the abnormal urine test? Do you feel that I should see a kidney specialist ?besides the urologist? Thank you for all your help!

    • Fredric Coe, MD

      Hi Gina, Uric acid stones can dissolve if the urine pH is increased to at least 6. Certainly high pH will prevent more. The dose of potassium citrate needed is determined by measurement. I presume your urine pH was low so you could produce uric acid in the first place. So now you have to measure again on the drug and see if it is high enough. The amount you are taking is modest. Higher doses are often needed. YOur physician can assure safety in knowing your kidney function and making appropriate blood measurements. One issue is how you know the stones are uric acid. Be sure your urine pH was really low before treatment as a kind of support for the idea. Perhaps you have some stone analyses? Regards, Fred Coe

  24. Eric Rounds

    Hello Dr. Coe,
    First, I am extremely grateful for your site and commitment to patient education. I had a stone 6 years ago. I had another last April, resolved by lithotripsy; an another in the kidney also resolved by lithotripsy in July. I was hit again this month (March), had lithotripsy, and then a horrifying blockage immediately after that procedure, resulting in a stent being placed for 10 days and removed today. My question has to do with prevention. I’ve been obsessively reading your website trying to get a handle on the info. Here are my basic lab results from last July (from litholink):
    Volume: 2.08 liters (normal or desired: 2.5 l)
    SS CaOx: 5.96 (6-10) LOW!
    Ox 24: 30 mg/d (20-40) NORMAL!
    Cit 24: 894 mg/d (>450) NORMAL to HIGH!
    Ca 24: 414 mg/d (normal or desired: <250)
    UU 24: 1.072 g/d (normal or desired: <.800)
    SS Uric Acid: 2.88 (normal 0-1.0)
    24 hr Urine pH: 5.330 (normal or desired: 6)
    Na 24: 185 mmol/d (50-150)
    K 24: 121 mmol/d (20-100)
    Mg 24: 147 mg/d (30-120)
    Sul 24 92 meq/d (20-80)
    UUN 24 21.96 g/d (6-17) (Urine Urea Nitrogen)
    PCR 1.6 g/kg/d (.8-1.4) (Protein Catabolic Rate)

    Cr 24: 3032 mg/d
    Cr 24/kg 31.1mg/kg/d (18-24)
    Ca 24/kg 4.2 mg/kg/d (<4)
    Ca 24/Cr 24 136 mg/d (<140)

    20% Calcium oxalate monohydrate
    80% Uric acid
    I should mention that for about three years I've been adhering to a low processed carb, high protein/fat diet that has been very effective maintaining a significant weight loss, and the reintroduction of much more exercise into my life. I recognize the probable link of lots of protein to uric acid stones.

    My doctor goes along with the notion that I want to have frequent 24 hr Urine tests to monitor concentrations, and to be very methodical in adding meds, so as not have multiple variables at work in my 24 hr urine results. Fair enough. But today he wants to starts me on 12.5 mg of hydrochlorothiazide to try to wrestle down the very high urine calcium level. He said once we have that under control, we can move onto the uric acid stones component. I guess after my very long-winded set up here is the question of why when my stones are apparently 80% uric acid stones we wouldn't deal with that first? His response to that question was that with that outrageously high Ca concentration, we need to deal with that first. He said something about the high Ca concentration of promoting the tiny crystal formation which may initiate the overall stone forming environment. He suggested that if I wanted to work on the uric acid stone component, I could have a couple lemons worth of juice each day and check the pH of my urine (I have strips). One final question that he didn't really answer is if my CaOx concentration is low, as is my oxalate, then how I am forming CaOx stones anyway?
    Thank you kindly.

    • Fredric Coe, MD

      Hi Eric, Since your urine pH is low, your uric acid SS is very high at 2.88 and your stone is mainly uric acid I would treat that part of your condition. You will need about 40 mEq of potassium citrate – 2 liters of crystal light lemonade or 4 10 mEq potassium citrate pills daily. I think your 24 hour urine is over-collected given 31 mg of creatinine per Kg of body weight or else you are a body builder with almost no body fat, so the total urine calcium per day may be overestimated. I do not know why you formed the calcium oxalate portion of the stone, but for the moment I would focus on the uric acid. Regards, Fred Coe

  25. Gayle Mullan

    Gosh, I am so thankful for the information you provide. I have been spitting out calcium oxylate stones from both kidneys since 1989. I’d have an attack about every two years since then. Finally, in 2007 I was put on the Urocit-K which slowed things down until now. Both kidneys have multiple stones , most of which are small but each one has either a 6.1 or 5.8 stone. I’m am working with a new Urologist now as I have changed states. He has me seeing a Nephrologist very soon. I am likely headed for some sort of procedure. My question to you is what can be done to lessen the terrible discomfort with the stent? I know hydration is a biggie but most of the time I feel that the stent is as painful as the stone! It makes me clench my teeth it can be so bad. Any suggestions? Thank you for your input!

    • Fredric Coe, MD

      Hi Gayle, Although it may sound like heresy, perhaps given all your stent troubles your urologist might try to do without a stent. Ask if that is possible. Regards, Fred Coe

  26. Mari

    Hello Dr. Coe, I have have read your articles on types of stones and on prevention. I would very much like to prevent any further stones. I did ask my urologist how I can prevent stones and his reply was that I have great questions to which there are not good answers. I have had 3 bout prior bouts of Kidney stones/pyelonephritis/urosepsis in 1992, 2007 and 2014, and now have multiple stones, largest being 1.1cm in the same kidney. The type of stone previously was Carbonate apatite Dahllite. I am overweight 33 BMI, pre-diabetic, and have multiple spinal congenital abnormalities, kiippel-feil syndrome, chronic back pain, IBD, chronic diarrhea and incontinence of stool, and recurrent UTI’s. Is it reasonable to think the recurrent UTI’s are the reason I develop kidney stones? Also, what could you suggest I do to prevent the kidney stones? Currently I keep myself hydrated and of course personal hygiene is critical. A Feb. 6, 2016 urine culture showed 50,000 to 75,000 cfu/ml
    Mixed urogenital flora, and urinalysis showed urine leukocytes 3+, blood small,WBC 120, RBC 19. I was put on a 5 day course of antibiotics but am still symptomatic with (R) flank pain. I last had a 24hr urine in 2014 after hospitalization for urosepsis and lithotripsy with results as follows: Citrate, 24-hr Urine 240 mg/24hrs
    Citric Acid,24hr UA 183 mg/g creat
    Urine Timed Creatinine 1.31 g/(24.h)
    I would be most appreciative for any advice on why I get recurrent problems and how to prevent the recurrent UTI’s and kidney infections/stone. Thank you!

    • Fredric Coe, MD

      Dear Mari, You are indeed complex, and given that I do not know the details of your urological situation I hesitate to say too much. Calcium carbonate stones are not specifically caused by infection – infection stones are made of struvite – magnesium ammonium phosphate – although it is possible that the struvite component was missed in the analysis. Matters are so complex here all I can offer to do is speak with your personal physicians, if they wish. It would not be an official consultation, but there would be no charge. Our site is complex but not sufficient for you. Regards, Fred Coe

  27. Barb Carroll

    When I take Potassium Citrate I get crippling muscle cramps, most often in my abdominal muscles. Anything I can do to counteract these? I get really sick of Crystal Light !

    • Fredric Coe, MD

      Hi Barb, I can imagine that drink – or any one drink – can pall after a while. The muscle cramps from potassium citrate is something I have heard about from a few other people. Is it related to the dose? After all a liter of the beverage is 20 mEq of potassium citrate, about that of 2 pills. Regards, Fred Coe

      • Barb Carroll

        I was taking 2 pills BID-TID depending on my urine pH. The cramps were debilitating. Nothing helped except stopping the Potassium Citrate. Oh well, I enjoy this site. I’m happy I have a local physician who follows up with me and does not just treat me rely on crisis management.

  28. georgeanne

    I’ve never experienced kidney stones until two years ago. My sister used to get them frequently. I was 66 at the time. I had two 3mm nonobstructing stones in the lower pole of the left kidney. I had Ureteroscopy two times. The first procedure failed as my uterers were two narrow, so I wore a stent for several months. The second procedure removed the stones and I obtained some relief but three months later two more stones were found, also in the left kidney.

    I have low Vitamin D levels which are being treated and raised alkaline phosphate but a complete bone scan was normal. The same thing happened about ten years ago, had the bone scan and the ALP returned to normal. I also had a DEXA scan which was normal. All other blood tests were normal as well as kidney tests.

    The only difference this time is I have Osteopenia and degenerative damage in the spine at L4,L5. I am getting a physical therapy evaluation soon. I also have Fibromyalgia which flares with the flank pain. However, there is a difference in the pain in the lower back which is very very minimal with no problems with mobility and the flank pain.

    I just had the 24 hour urine tests and got the online results. It looks normal but I’m not a medical professional. I see the urologist next week.

    Any comments are appreciated as I’m not sure what should happen next. I’m thinking of getting a second opinion. It’s not so much that I don’t like my urologist but maybe another pair of eyes might be helpful.

    One more question. Can you have secondary hyperparathyroidism from low vitamin D and still form stones? My calcium levels are normal.

    Apologies for the length of this post.


    • Fredric Coe, MD

      Dear Georgeanne, I am guessing you have idiopathic hypercalciuria and have indeed had episodes of low vitamin D. Check the urine calcium. Is it above 200 mg/day or above 140 mg/gm creatinine? Osteopenia could be postmenopausal in origin but IH also causes it. Given the stones I doubt that your 24 hour urines are normal so much as they are possibly deceptive. What are your stones made of? Some were removed by URS so you must know. Write back with more information. Regards, Fred Coe

      • georgeanne

        Thank you for the timely response.

        I believe the stones were calcium bit need to check with my urologist. My urine calcium was 211.

        Are you talking about creatinine blood test as I can’t find it on the 24 hour urine test. Is it called something else? My blood creatinine is 8.3. I should mention that in the two years of having this, I have lost 25 pounds without trying. I have always been very thin and small boned but when put on several medications such as SSRIs as well as clonazapan for RLS and other sleep issues, I gained weight. The flank pain if severe enough makes me nauseous and overall a reduced appetite. I also have IBS but have had that for years.

        Again thanks. This site is incredible!

        • Fredric Coe, MD

          Hi Georgeanne, your urine calcium is a bit high, enough to increase stone risk – follow the link. Your serum creatinine is 0.83, I am sure, which is normal. On the 24 hour urine report look for ‘Cr24’ if you cannot find the word creatinine. No 24 hour urine is any good without a creatinine value to estimate the quality of the collection. I am pretty sure you have idiopathic hypercalciuria and possibly some worsening of bone quality because of it. Diet should be high calcium for your bones and as low a sodium intake as possible. In some cases, when stones are active, thiazide type diuretics are used, but in your case diet has not been tried as yet. We have an excellent article on low sodium diet. Regards, Fred Coe

          • georgeanne

            If I have idiopathic hypercalciuria as well as the raised ALP but not Pagets, should my two daughters be tested for this? My older daughter is forty and younger daughter 35. My sister used to get stones but think it’s been several years.

            I think at this point I need a second opinion. I talked to the nurse at my urologists today as it turns out my appointment is week after next not this week.. My urologist is saying my 24 hour urine test is normal but in his defense that may have been his interpretation just glancing at the test since since he also had appoinments which understandably are his priority for the day. There is nothing about creatinine on the test which was sent to Mayo Clinic so this surprises me. Is this usual?

            Should I see someone in your or a similar clinic or an endocrinologist who specializes in bone metabolic disorders (?). I live in Champaign about two plus hours from Chicago.

            In the meantime, I am very uncomfortable and there’s increased pressure in my left flank. I have never passed any of my stones and don’t think I am now as I am more uncomfortable than in pain.

            I think my diet is okay but need to double check your reference. I rarely salt food but do know there are other sources, no red meat and avoid processed foods. I think my calcium intake is high normal but maybe need more?

            I know there are limitations as to what you can advise without actually seeing a patient and don’t expect you to answer all of my questions but listed quite a few and will let you choose.

            Thank you for your time.
            Kind regards.

            • georgeanne

              Almost forgot. Several years ago my sodium levels were extremely low and would fall to 125 as well as several hospitalizations. It may have been induced by Trileptal as when the doctor took me off of it the levels have since been normal.

            • Fredric Coe, MD

              Hi Georgeanne, I think you do have idiopathic hypercalciuria – normal ranges have altered in the past few years. If you do indeed have this your daughters have about a 50% chance of having it too. Likewise your sister who formed stones. As for your personal care, I will email you as that would be inappropriate on a public site. Regards, Fred Coe

  29. Carla

    Hello Dr. Coe,
    I am so encouraged by your website, and impressed that you take the time to answer comments and provide such valuable information. I am a 57 year old female, and have been dealing with stones for over 30 years. Years ago I was prescribed loads of antibiotics because I would present with UTI symptoms and no infection, but they treated anyway. I now feel that was due to stones. Most of my care has been crisis management. Over the years, I have passed stones, had one dealt with with lipotripsy, and have had two uretoroscopies, the last one in Dec. 2014. It took doctors almost a year to figure out that the problem I was having was a stone because the xray and ultrasound didn’t pick up the 9 mm stone due to its position related to the pubic bone. It seems that my stone issue has really reved up since about 2005. Since the last stone removal (2014) I have had off and on symptoms of stones – some kidney pain, pelvic pain, urinary issues, blood in urine, etc. My urologist is so busy that I don’t usually get into see him until I am in crisis and need tests. He has done a 24 hr. urine test (2009) but never really followed through on prevention except to tell me that I may have hypercalciuria and to drink water. I had a CT scan in 2013 and he said I may have MSK. I did consult with a urologist at UCLA (March 2015) and he was not convinced of the MSK. He did a 24 hr. and also stated hypercalciuria and recommended water and the DASH diet, with possible Thiazide in the future. He did a Vitamin D, 1, 25-Dihydroxy test and my result was 87 which was out of standard range. Suggested I see a nephrologist (he gave me a name) but that it wasn’t urgent. I have not done that as of yet. My 24 hr. urine (the dates are 5/3 and 5/4 so it was a 48 hour, the measures are for 2 days) in 2009 (Litholink) showed Ca24 of 286 day 1 and 254 day 2 with Ox24 being 34 day 1 and 27 day 2. My volume was low day 2 (1.38) but ok day 1 (2.28). Other out of range numbers – SSCaOx 5.52 day 1 and 8.42 day 2, SSCaP 2.25 day 1 and 2.71 day 2, pH 7.097 day 1 and 6.493 day 2, and UA24 .740 day 1 and ok on day 2 at 0.554. Since then, I had another doctor do a 24 hr. through Quest Lab on 4/14/14 that stated ‘no metobalic abnormalties’, and the doctor reported that my numbers were perfect. The following is the results for the latest Litholink 24 hr. through UCLA urologist mentioned above (date- 4/17/15):
    Vol24 – 3.15, SSCaOx – 4.47, Ca24 – 188, Ox24 – 41, Cit24 – 873, SSCaP – .47, pH – 6.076, SSUA – 0.35, UA24 0.598.
    Currently, I was in the ER last Thursday night for abdominal pain and was told that I had a gallstone blocking a duct. I was sent to a surgeon on Friday to discuss gallbladder surgery. On Sunday, I started having significant stone symptoms which has continued to be present. I see my GP on Friday for a consult on the gall bladder. I also take a blood pressure med (for about 15 years) (Toprol-xl, 25 mg.), and have had body pain issues (about 15 years) which seem to be arthritis, I assume, due to observing my hands becoming a little disfigured over the last several years (blood tests have never shown anything). My daughter has had a stone, and my older sister has had several (not for many years) and was told she has parathyroid issues but has done nothing about it. I had an older brother that died of Bright’s disease at 2.5 months old.
    I am sorry this is so lengthy, but I am looking for any insight you may be willing to give. I am a bit discouraged, and do not know where to go from here. If you have any recommendations of physicians that may follow your treatment protocol in the southern California area I would highly appreciate the referral. You can contact me at the email provided. Thank you for your time.

    • Carla

      You are welcome to publish my comment. I meant that you could email if you have a referral. Thanks

    • Fredric Coe, MD

      Dear Carla, I understand you have had calcium oxalate stones and presumably have multiple stones in your kidneys – otherwise your physicians would not consider MSK. I cannot tell if you are having recurrent stones or pain and bleeding without actual stones. You have stones formers in a daughter and older sister. Your urine studies 5/3 and 5/4 2009 show a high urine calcium 286 and 254 mg/day, oxalate 34 and 27 mg/day, and volumes of 1.36 and 2.28 liter/day. A new set of measurements 4/17/15 showed a calcium of 158, oxalate 24, citrate of 873, and low supersaturations. You also have high blood pressure and a recent gall bladder stone. You do indeed have hypercalciuria and with your past 1,25D test at 87 and I presume a normal blood calcium and PTH value it is idiopathic hypercalciuria. This latter is strongly familial and inherited. Assuring a normal blood calcium and PTH is very essential as is ruling out any systemic cause of hypercalciuria. I do not know your treatments at this time, but I suspect this: The urine volumes were perhaps not exactly representative of your overall real life and can be lower during your usual work or other activities. I say this because with your current modest calcium and oxalate losses, and high citrate excretions and low SS for CaOx and CaP you should not make any crystals or stones. I would be sure that my urine volume was over 2.5 liters a day every day, and steady over the day. If you are having pain because of passage of prior stones, which is also possible, perhaps your kidneys could be cleared via flexible digital endoscopy. But I would not do this until I was confident I could keep the urine volume high and steady as I just mentioned. The high 1,25 D level is not uncommon in idiopathic hypercalciuria, by the way and is not a problem in itself. The urologist at UCLA sounds like the best bet, and I would discuss your clinical stone/pain issues with him/her and benefits of clearing prior stones. Warm Regards, Fred Coe

      • Carla

        Thank you for your quick and thorough reply. Much apprciated. I will continue to pursue medical care with UCLA. I read the article you wrote about treatment protocol with the proper follow-up, etc. I do wish doctors would follow this. It really makes sense. I may print it out and give it to my doctor! I do have stones in my kidneys currently. Last time I went to my local urologist (not UCLA dr.) that’s what prompted him to to say the best he could do was to see me when I have my next stone issue. No real preventive care. That’s what lead me to seek help at UCLA. I will bring your recommendations to my next appt. Thank you. Again, your site and your insight are much appreciated. 🙂

        • Carla

          I do have one other question. My regular vitamin D levels seem to hover between 28 – 35. My primary care doctor is always pushing me to take D3 with K2. He says that this should not increase stone formation. I have researched this on the internet but have not found much. Do you have any thoughts on taking Vitamin D and its effect on stone formation? Thank you.

  30. Ryan

    Dr. Coe,

    Why don’t urologists prescribe pyridoxine more often in hyperoxaluria? Doesnt the data show a benefit in patients with idiopathic disease as well as primary type 1 hyperoxaluria?


  31. Albert

    Please help. My ultrasound reports as below.
    Findings: Bilateral non-obstructive renal calculi are domenstrated. The largest on the right is a the uppoer pole measuring 1.8cm. The largest on the left is at the mid to lower pole measuring 1.2cm. No hydronephrosis.
    Impression: bilateral non-obstructiverenal calculi.
    Can someone please explain this report to me, as my family doctor in Vancouver, BC, Canada, could not say much about it to me and just told me that it is very common in Asians. What does No hydronephrosis means? Is there any way to cure the present condition of my kidney stones? What should I do it? I just met my doctor today. He said there is not treatment or medication for this. I would appreciate your help.

    • Fredric Coe, MD

      Hi Albert, it sounds as if you have multiple stones in your two kidneys, several of which are rather large. I do not agree that nothing should be done. If the present stones are not obstructing, nor causing significant pain, infection, or bleeding there is no surgical urgency. But why are they forming? Prevention of more stones is an urgent matter as being Asian is not a reason to make stones – there is something causing these and that something needs to be identified and remedied. You should attempt to get your physicians to find out the cause and offer appropriate prevention services. It is not true that there is no treatment for stone prevention – Regards, Fred Coe

  32. David Hawkins, AL

    2yrs ago I found out I had a very large stone, larger than 2cm called a staghorn calculi, the stone is 60% COMonohydrate, 30% Calcium phosphate, 10% CODihydrate. After 2 lithotripsy surgery’s it is almost gone. I drink 1.5 gallons of water a day is there anything else that helps. I have read the diet the doctor gave me and I don’t eat extreme amounts of any of the food that was on the chart.

    • Fredric Coe, MD

      Hi David, There is a lot more that should be done. What did your blood and your 24 hour urine tests show? Surely there are some abnormalities, and these need to all be treated. The high fluids are a good think. I presume the diet lists concern oxalate. What about urine calcium, urine citrate? Was your urine volume much lower in the past? Did you eat differently? Were your 24 hour urines – if collected – collected during a period approximating your stone forming life?? Many things can help, but everything begins with what is there as a cause in the first place. Regards, Fred Coe

  33. Richard Thomas

    Dr Coe
    You state that the process in the kidneys is the formation of crystals and supersaturation drives the formation
    and growth of the stones/crystals. My particular interest is in uric stones.
    Uric acid supersaturation can form stones in the kidney/s, or in the blood uric acid crystals, causing gout.
    The process in the kidney/s is supersaturation not necessarily causing crystals but rather deposition stones.
    Please comment. Thanks.

    • Fredric Coe, MD

      Hi Richard, and thanks for the question. Uric acid stones are aggregates of uric acid crystals – no crystals no stones. Sometimes the crystals do not clump together to make stones and patients pass uric acid gravel which is orange because the crystals adsorb a urine pigment (uricine – a hemoglobin breakdown product). Often the crystals do clump and form stones. The molecule that makes these crystals and stones is uric acid on which both proton binding sites are bound to protons. This makes both sites less negative and offers water molecules less to hold on to. The rest of the uric acid molecule is very hydrophobic – no charge sites – so water cannot hold it in solution. The solubility of fully protonated uric acid is about 95 mg/liter. Given perhaps 600 – 700 mg of total uric acid a day in urine, and perhaps 2 liters of urine this would make a supersaturation of 300/95 to 350/95, which is very high. The second proton binding site is 1/2 occupied at a urine pH of 5.35, so at a pH of 6 it is fully charged and available for water – the solubility of the monohydrogen urate salts of sodium, potassium, and ammonium (available positive charge partners in urine) is very high, and these salts almost never cause stones. In blood the pH is 7.4 so the relevant salt is sodium monohydrogen urate, which is just at saturation when blood total uric acid is around 8 – 10. This crystal form is what makes for gout – a different crystal from the urine. So, everything is always the same – supersaturation, crystals, and trouble. In joints we get crystals and they cause inflammation. Regards, Fred Coe

      • Steve

        Hello Dr. Coe,
        Just by chance I came across your article about uric acid kidney stones and it really caught my attention as I have been searching high and low and have yet (until now) to find a decent explanation. I do have a question. I was diagnosed with MSK (left kidney only) about 40 years ago. Up until last year, I never had any obvious symptoms. In January of 2015 I had my first ever episode of kidney stones. Pain was minor and I passed a 2mm stone (confirmed as 100% uric acid) along with many small sand-like stones. To make this story short, ever since then about every two to three weeks, I will pass sand-like stones for a day then not again for several weeks. Nothing larger so far thankfully. I have been seeing a nephrologist and urologist. I have adjusted my diet, been drinking more water mixed with lemon juice in hopes that this would stop. Can you offer any insight as to what caused this to start up suddenly after 40 years? Thank you!

        • Fredric Coe, MD

          Hi Steve, Your stone was 100% uric acid, and that is prevented completely by raising urine pH with suitable alkali. These kinds of stones are due to an acid urine pH that can come up later in life. Get proper 24 hour urine testing which will show the problem and treat it as noted in the article. The sand and stones will stop. Get the gravel analyzed to be sure it is all uric acid. regards, Fred Coe

  34. Curious to know

    Thank you for the informative article. What role does Hyperparathyriodism play?

    • Fredric Coe, MD

      Hello Curious, hyperparathyroidism is an endocrine disease that causes stones and bone disease, and it almost always curable with surgery. I have not written much about it on the site but there is something here in the article on hypercalciuria. It is on the list of diseases that physicians need to look for in calcium stone formers. Regards, Fred Coe

  35. Jeannie Martin

    I have finally found a urologist that has taken an interest in resolving my stone problem. Last 15-20 yrs have been unbelievable and expensive. Your website and many people on facebook have given me insight into the changes to makeand follow I need. In Jan I have a f/u appt from last April laser to rt kidney and have had very few passable stones since. Have had stones bil but rt has been worse along with rt multiple inf that never cleared up until after this surgery. So am curious to see if more stone formations…prior to appt am scheduled for 24 hr urine, ultra sound and xray…thank you for your web site and the awesome work you are doing….Will keep following.

    • Fredric Coe, MD

      Hi Jeannie, You are doing the right thing to figure out if there are new stones forming. If there are, then you need more prevention oriented changes to lower supersaturations. Exactly. Fred Coe


Leave a Reply