MeBeing chronic in many cases, stones need to be prevented not just removed. That accomplishment, prevention, needs the skills, efforts, and cooperation of two people. I am writing this for the one who makes the stones, and my purpose is to promote success: No more stones.

I have never known physicians who do not want successful treatment for their patients. It is the ultimate satisfaction. But they are time pressured, as are we all in this hectic world, and you can help by doing before and after a visit all that you can do to make the visit time count – to waste as little as possible, and put to use as much as you can get by way of treatment.

I have cared for thousands of patients with stones. Here are things patients do that help me with their care. If you do them before and after your visit for stone prevention things might turn out even better than they would have otherwise.

This article is meant to complement my other one on the Five Steps to Stone Prevention.


Gather Your Materials


history listClick on this outline and it will open as printable or downloadable as an image. This will help you make your document.

Type your history neatly. These headings are designed for a kidney stone patient and are not meant to cover all aspects of health care. Because this will be a focused visit it is best to keep the history on target.

The dates of stones are often only to the nearest year, and that is alright. For procedures the best source is old bills which are dated and name the procedure, or, even better, old medical records. Complications and urinary tract damage usually require medical records for documentation. The same for your other medical conditions and past surgeries apart from stones.

Medications can be confusing, Try to focus on prescription drugs, and mention what they are or were for. Supplements, herbs, health food concentrates can cause stones, so be as specific as possible: What, how much, how long.

Because idiopathic hypercalciuria and low calcium diets can both cause bone disease, your diet and family history of bone disease matter. About your own diet, besides calcium intake, critical components for stones are protein and sugar intake, oxalate intake, and fluids.


Do not be shy. By law your medical record belongs to you and you are entitled to reports and DVDs of your radiographs. Usually there is no charge.

Resist attempts to have them sent to your doctor. They may not get there even though everyone means well and tries hard. Do not believe that electronic medical records will have your information. They may well not.

What you will have is what you bring in your own hands.

  1. All stone analyses – bring actual reports
  2. Prior records related to stones
  3. kidney stones you have in your dresser drawer. It is important to analyse all stones.
  4. CDs of most recent CT, or other radiographs or ultrasound images for stones
  5. Recent blood measurements, bring actual reports: Serum calcium, phosphate, creatinine, potassium, chloride, total CO2 are most important
  6. All 24 hour urine kidney stone tests to date – bring actual reports not summaries

24 hour urine test results can be complicated to get. Vendors send the results to your physicians but a lot can go wrong. Electronic transfer to electronic medical records can be unreliable. Faxed reports are sometimes lost.

Get the reports sent to you, and bring a full copy with you.

If the laboratory cannot release the report to you – some states have laws about this – call the vendor and get the report faxed there. Call the physician’s office and be sure that it has arrived.

Do Your 24 Hour Testing Well

  1. 24 hour urine testing is essential for prevention, and only you can assure the tests are useful.
  2. Be sure testing is done by one of the large national laboratories, not a local hospital laboratory. The latter is often not properly equipped to do this kind of work. All national vendors in the US are fine.
  3. Do the tests before your visit; without them, the visit will be vague and incomplete.
  4. Read what Jill Harris says about collecting urines – I repeat some of her ideas here


All of the vendors provide containers and instructions; follow them exactly. If you think you have made an error, discard the whole collection and call for a new kit. Never try to ‘fix’ an error – you cannot do it and the results will be an expensive and misleading mess.


Do two 24 hour urines so one can be on a weekend and one during the week. The latter should be during a regular work day if you work outside the home. Two samples are very important because even though results on one day are well correlated with results on another day there is a lot of spread between them, and that spread is useful to your physician in planning treatment. The two samples need not be continuous but it is preferable if they are.


Never show off; never make collection days special.

You are selecting 2 frames from a movie that is life long, two days out of thousands.

Make the two days represent you as you are in general, as you usually eat and drink, work out, work, and get around. Just go about life as if you were not collecting. Especially, drink as you always do. The large container often goads one into trying to fill it.

If you see the jug is almost empty at the end of a full 24 hours, it means you do not drink enough, but don’t choose that moment to reform and correct matters. It was like this you made stones, let your physician see the chemistries as they were.

What To Bring To Your Visit

It is folly to believe anything can be sent to a physician, and folly to believe ‘it will all be in the computer’. In my life, at least, nothing ever comes by mail, and computers are as unreliable as rural mailmen on horseback in 1790.

What you bring with you, in your own hands, will be there. Do not give anything up until you reach your physician. Hand the materials to him or her.

Here is my list:


The time will be limited, and the information dense and fast coming. Even if you are young and brilliant, you will have trouble because it is you who will be the object of attention. The other person can keep facts straight, write things down, ask questions you may miss on the moment. I shall call this other person your advocate.


What to Bring

The master list. As I did for the history, this is an image file you can print or make into a card for a reminder. It summarizes everything up until now in a compact form.

Plan Your Visit Carefully


Sometimes a primary care physician who knows you well will undertake prevention. This has the advantage that history taking is abbreviated and a relationship is already established. That will leave more time for the details of stone management.

Urologists often practice stone prevention, and it may be your surgeon you will be seeing. That also has the advantage of pre-knowledge. Surgeons often schedule very brief visits, but can be expert in this particular kind of medical care.

Sometimes you will have been referred to a nephrologist or other physician who is expert in stone prevention but does not know you. The advantage of specialization is balanced by a greater time required to become familiar with your situation.


You are purchasing time for yourself, and you need to make that time work well for your care and fit into what your physician needs to do.

Find out how long you will have with the physician. Since it is all about time, how much will you have? Each of the three physician archetypes I have mentioned have specific time issues: The better you are already known the less total time is needed for background the the higher fraction available for the specifics of stone prevention.

Usually physicians have allocated a fixed amount of time to a first visit for kidney stone prevention, so you need to know the usual practice. Typical times for busy medical practitioners can be short – 15 to 20 minutes total with at least 2 – 3 minutes used up for the computer. This generally leaves about 12 to 17 working minutes. Surgeons often have no more than 5 – 7 minutes for a visit but use nurses with advanced training to help and, being surgeons, tend to a high level of organization and accuracy.

Review your history with your advocate so you can present it to your physician efficiently. He or she has to produce a legal medical record, and may need to type it into a computer. All this takes time. Go over your questions, and your list of what you want to leave with.

The Usual Sequence of a Visit

First is the history which you have made as convenient as possible.

Next your physician should want to view your DVDs.

The most important part is to count how many stones are already in each kidney – this is your baseline for treatment. If you pass a stone during treatment, it may well be one already present at this initial visit, and that is not a cause to change treatment. But if new stones appear on a subsequent CT, or you pass stones and the numbers on a subsequent CT are unchanged it means stone disease is ‘active, you are producing new stones, and treatment is not yet successful.

This initial tally of stones is a crucial event for you. Be prepared to ask how many your physician sees, and write it down, left and right side separately.

Although physical examination is a central part of clinical medicine, I have found over decades that the yield of findings that affect kidney stone prevention is minimal. I believe most physicians have found the same. Done or not is simply a matter of time left for what comes next.

That next will be a review of your serum and 24 hour urine tests, and your physician will no doubt interpret them to you in terms of what seems to be causing your stones and what can be done about it. The laboratory results are always interpreted in relation to the composition of your stones which are from the stone analysis reports.

The last part, and most crucial for you is your treatment plan and follow up routine.

Plan to Facilitate Each Part of the Visit


Being written down, and accompanied by old records, laboratory reports, and medication lists, the history taking should go smoothly. Avoid introducing extraneous stories or minor details. You are seeing a physician who is trained especially in history taking, and will lead the conversation. As much as possible, follow that lead and try to add details you are asked about. Here is where your advocate is most helpful if a spouse, family member, or very close friend.


I hesitate to mention the matter, but possibly not all physicians will personally view the CTs and count stones. As best possible bring this matter forward. Without this baseline matters will become foggy during treatment. I have been impressed that official radiologist reports of CT scans are often not quantitative about the numbers of stones in each kidney.


The review of labs is central. You and your advocate need to follow as best is possible, and at least one of you write things down for later. Ask questions, do not let things go by you do not understand. The review is for you, and what you do not understand has not been presented well enough.

Serum lab results are critical, along with your medical history and past records for diagnosis of systemic diseases that might be causing your stones. I have tabulated the commonest ones for you, and their main laboratory abnormalities. You cannot evaluate systemic disease diagnoses yourself but you can cast a critical eye on your own lab results and ask questions.

I have written two articles that enable you to read  your own 24 hour urine lab reports intelligently – I mean by this with enough knowledge and expertise to understand the numbers. If you know  your stone type review the article for that stone type: Calcium stones; Uric acid stones.


Management of Stones Already There

You should expect an assessment of the stone disease to date – numbers of stones, evidence of kidney injury if any, amount of the stone burden – how many stones, how large, risk to the kidneys if any. Most important, is there a need for more surgery or can the stones be left in place?

My view is that stones do not need surgery unless they are producing obstruction, significant pain, substantial bleeding, perpetuate significant urinary infection or are a threat because some abnormality of your kidneys or urinary tract will make passage especially hazardous. If surgery is recommended, here is the time to ask why. Just being there is not enough for me, most of the time.

Cause of Stones and Approach to Prevention

Your serum and urine testing should permit an overall analysis of what causes the stones, what you might have done in the past to foment stones, and in general what will lead to prevention of more stones. This is a most crucial area. Make notes, and think through any part of the presentation that is not clear. This is where your advocate can be helpful. Do not let this moment go by without understanding what has been said.

Sometimes, the cause of stones will be tracked to a systemic disease, and that will shift matters from fluid prescription, diet, and medications to alter urine chemistries to the management of that disease. In that case, it is critical to understand the basis for the diagnosis, further testing, and treatments that may be used.

Treatment Plan for Prevention When Systemic Disease is Not Present

Apart from the uncommon situation of systemic diseases, prevention is always about fluid prescription, diet, and medications.

Fluid prescription should consider urine abnormalities including supersaturation, and also the realities of your life, work, and when relevant limitations such as incontinence and sleep disorders, the one posing a problem for high fluid intake by day the other by night. Review your present urine volumes and how much of an increase is needed.

Diet will seek to correct problems observed in your 24  urine studies. Ask to see the abnormal laboratory results you are treating, and compare your results to the normal values and to goals you are to achieve. Common abnormalities are high urine calcium, oxalate, sodium, or uric acid, or low urine citrate. Ask about priorities: It is hard to change everything; can you focus on some of the problems at first and others later?

Medications for common stones are potassium citrate and thiazide diuretics. The former is for prevention of calcium stones or uric acid stones. The latter is to lower urine calcium excretion in idiopathic hypercalciuria.

Follow up Plan

There is no sense to treatment without follow up. If you are to change your fluid intake, diet, or add medications, you need to be rechecked with 24 hour urine testing to be sure the desired changes have occurred. If this is not mentioned, ask about the matter and have a plan. In general it is best to wait until changes have been made and followed for some weeks to be sure they can be tolerated and maintained. Be clear about how new testing will be arranged. Although the new results can be communicated by phone or mail, it is best to review things at least once in person.

Your Questions

You can see the problem. If you have special questions, they will tend to be squeezed in at the end, and may not get fully answered. Have your list in hand, and fit them when possible into the flow of the conversation. If some are really urgent, let  your physician know and set time aside for them.


Begin Right Away

While things are fresh in your mind, increase your fluids, make diet changes, and begin meds if prescribed. If you can, compare what you are doing with what  your advocate heard at the visit, and consult your notes. If you are confused, call the physician’s office, or email, and ask if a nurse or the physician can clarify matters.

If some things are impossible, likewise. Do not wait for the follow up visit to say that, for example, your job involves so many long meetings you cannot maintain the desired urine flow, or that a higher calcium diet is being limited by intolerance to dairy products.

Use every means possible to create the program in real life that your physician proposed to you, and try to make it work most of the time.

Follow the Treatment Cycle

VIRTUOUS CYCLE 1Being chronic, often a reflection of genetics, stone formation is not so much cured as managed, by fluids, diet, and drugs. Lacking cure your physician and you need to stay in the loop together, a loop I call the treatment cycle. The inner ring is a three month cycle to get urine chemistries into line. The outer ring is a yearly maintenance cycle once things are stable.


You already began, when your physician identified stone forming abnormalities in your urine and prescribed fluids, diet, and possibly medications. That is you, just to the right of the bold ‘BEGIN’ sign. The secret to success in preventing more stones is retesting to be sure the right things happened, and I have always preferred 3 months as an interval.

There are only two outcomes. Success means the abnormalities are corrected. You leave the inner ring and retest 12 months later.

Failure means not all are corrected, so you stay in the inner ring, work with some new combination of fluids, diet, and possibly drugs, then retest again in 3 months. You should review the new tests with your physician. One day you will achieve control and go out into the outer ring, yearly testing.


It is here things fall apart. The yearly cycle is insurance that changes in you or your life have not altered urine chemistries enough to recreate the stone forming condition you came with. It is burdensome, and costs money, but even one shock wave treatment is thousands of dollars, often requires a stent procedure, and therefore far more of a trial. For the yearly testing, be sure and review results with your physician. Sometimes physicians will review results, find them perfect and just send a note. Sometimes email or a phone call is enough. If results are very abnormal or remain abnormal on repeated testing, a visit is preferable.

Stone Attack or Bleeding Despite Good Control

Write down the date and indicate if you think you know why it happened – eg. 6 hours at a soccer game with no fluids; a flight to Asia and back. Perhaps there is no inciting cause. Because you are being treated ‘successfully’, any event is important to understand. Did you have many stones at baseline? Did you have none? At some point a new CT may be needed to count stones and determine if you are still actively forming them. This is a complex medical decision, so your physician is key and needs to be informed.

I have already pointed out the issue with continued stone activity despite treatment, and will repeat myself here. Ultimately stones are made of crystals, crystals obey physical laws, and the key law is that supersaturation is necessary – if not sufficient – for crystals to form and grow, and even to remain stable and not dissolve.

Whatever the status of treated urine abnormalities, the net aggregate summary of your urine chemistries is supersaturation with respect to the crystals in stones you are forming. If you are actively forming new stones  your urine supersaturation with respect to their crystals is too high and needs to be reduced further even if all of the individual components of stone risk in your urine – volume, calcium, oxalate, phosphate, pH, citrate, uric acid – are all within normal ranges. How your physician chooses to lower that supersaturation is likewise a complex medical matter, and you cannot do it alone.


No prospective, randomized, double blind trial supports my cycle, and never will, because it is not a treatment but a way of using the components of treatment. We have one trial of fluids, and multiple trials for potassium citrate and thiazide diuretics. So the components work. But, they do not work without a structure. The trials had a structure, after all, even if it was simply to assure the drugs or water were being used. My cycle is much the same, except it assures as best one can that the treatments being used are doing what was intended.

from durable stones - stone free survivalHowever, I do have long term observations, and though they do not prove what I do will work for you they demonstrate what I accomplished with patients in my practice who stayed in the cycle.

Here are five cohorts of stone patients who entered 0-5, 5-10, 10-15, 15-20, and >20 years ago. All five of these life tables are similar – they do not differ significantly from one another.

The five year cohort – black circles was >85% stone free by 5 years, the longest possible follow up interval. All of the 5 cohorts showed a gradual decay into new stones, but even for the longest observations – >20 years – 60% had been stone free.

Even those not stone free did rather well. In the paper we show the numbers of stones per patient before and during treatment. Before treatment patients in the five cohorts formed between 1 – 2.5 new stones adjusted for the duration of the pre treatment stone interval. During the years in treatment, rates adjusted for duration of treatment ranged from 0.04 – 0.14 stones per patient, a fall of over 10 fold.

fraction without proceduresRates of procedures fell even more dramatically. Procedures were frequent at the beginning for all cohorts. That is why the curves of procedure free state fell sharply from 1 to 3 years. Thereafter, all five cohorts showed a plateau, and after 15 years we had no procedures to count – thus the graph ends beyond that point. So what few stones did pass caused little by way of surgery.

There is much in this observational paper to quarrel with. The successful patients are those who stayed in the program, but what happened to the many who left? Why did so many leave? Perhaps those who stayed were otherwise remarkably vigilant, or perhaps blessed with a finer biology than those who left and the latter continued to make stones despite my treatments. Probably many who left also left off treatment.

I say all of this is correct and maintain only that can say what happened to those who chose to stay, and it is as this graph shows – imperfect but not bad. I could also say I am not unjustified in recommending my cycle to others, physicians and patients, because it is sensible to treat and look, adjust and look again, and be watchful when new stones keep coming. Likewise it is sensible to stay in partnership with your physician, or with your patients if you are the physician.


I have described my own practice on this site, and anyone who reads that description could say I have been disingenuous here. Not so. My practice is within a university, designed to support research as well as treatment of patients, and therefore subsidized by society and disconnected from the travails and limitations of real life. I set out to gather and retain data from every patient, so I work most slowly and take more time than physicians can who pay office rent, a nursing staff, and need to support their families from the proceeds of medical care.

But I could practice excellent stone prevention within the common limits of clinical life if patients were willing to organize things as I propose here. I have not proved this assertion, but after so long a time at this one task will you not accept my judgment is probably reasonable?


Physicians evaluate and treat people, but educated patients can help themselves and their physicians in so many ways. I have made links throughout for that general purpose, and the site has quite a bit about the causes and treatment of stones.

When you have your diagnosis, treatments, laboratory abnormalities, feel free to browse here and read about what is being treated, or what has been found. Knowledge may not improve your treatment outcome, but it cannot do any harm.


  1. Connie V.

    Thank you so much for all the information! I have sarcoidosis, determined by a lung biopsy. I also have recently had 2 kidney stones, a 5 mm I passed and a 7 mm that they used shock wave therapy on. Both were 80% calcium oxalate and 20% calcium phosphate. I still have a 3 mm one in my other kidney. My urologist scheduled me for a CT scan in a year to see if that one has grown or if I have developed new ones. I have read what you have written here about idiopathic calcium stones since I have been unable to find anything specific on treating these in a person with sarcoid. I was wondering if you would treat these the same in my case as you would for those with idiopathic calcium stones. I have had blood tests, the last one where everything except creatinine fell within the reference range. That was 1.0 mg/dL and reference range was 0.5-0.9. My GFR was 57.61, which I know is low. I am 74.

    I had a 24-hour urine test in which these were the results that were not in the threshold range:
    High risk for stones:
    Urine calcium 460 reference range mg/d <200
    supersaturation CaP 2.14 reference range 0.5 – 2
    24 Hour Urine pH 6.830 reference range 5.8 – 6.2
    Urine Phosphorus 0.906 reference range g/d 0.6 -1.2 g/d
    Calcium/Kg 7.6 reference range mg/kg/d <4.00
    Calcium/Creatinine 420 reference range mg/g 550
    Supersaturation Uric Acid 0.04 ref. range 0 – 1
    Urine Uric Acid 0.460 reference range g/day <0.750

    I have been on a low sodium diet for years, due to my Meniere's, and the nephrologist has suggested I also go on a low oxalate diet, which I have started. As previously stated, I drink lots of water throughout the day.

    From what I've read, thiazides should be tried for this type of stone. However, I was previously on a thiazide 3 years ago for Meniere's and it caused hypercalcemia where I want to the ER and was told my kidneys were ready to shut down, so I cannot use this type of medication. My nephrologist is trying potassium citrate, starting at 5 MEQ tablets twice a day in order to try to bring down the calcium in my urine. She will see me again in a month, take a blood test, and if things go well, wants to up the dosage. I know this is also something you have suggested. However, I am having a difficult time with the potassium citrate as it is causing pain and nausea even though I am taking it with food and drinking a glass of water before and after the meal and am still on a low dosage. I am wondering if this will go away as my body adjusts to it and, also, if you have any other suggestions for a person with sarcoidosis, which my urologist believes is the main cause of my stones. Do you think the Crystal Light, etc. would work instead of the potassium citrate in my case? Thank you so very much for any help you may be able to provide since I just haven't been able to find anything on treating kidney stones in people with sarcoidosis.

    • Fredric Coe, MD

      Hi Connie, You do indeed have marked hypercalciuria and sarcoidosis may be the cause. High calcium from sarcoidosis is itself from increased levels of 1,25 vitamin D that can be measured. Because of the high 1,25D serum PTH is suppressed. Can you tell if you have such information? Having sarcoid and high urine calcium does not mean the sarcoid caused the high urine calcium. You say you follow a low sodium diet; what was the urine sodium in that sample? If you provide more I can try to be more helpful. As for potassium citrate, is your urine citrate low? It is not useful in general, only when needed. Regards, Fred Coe

      • Connie V.

        My urine sodium in the sample was 98 with the reference of mmol/d 50 -150 and my urine citrate was 738 with a reference range of mg/d 550. I do not have my level of 1,25 vitamin D and don’t think I’ve ever been tested for that but my urologist told me not to take any vitamin D supplements. I had been tested for plain vitamin D, which came out low. My PTH was 27.9 pg/ml. with ref. range of 15.0 -65.0. Hope that helps.

        • Fredric Coe, MD

          Hi Connie, Given a normal citrate there is no basis for taking citrate. Your PTH is normal, not low as expected when sarcoid raises urine calcium. Your urine sodium is not low, it is at the US tolerable upper limit. 1500 mg is ideal, and at least try to get there as a way to lower urine calcium. Ask your physicians about this remark and be sure they agree. Regards, Fred Coe

          • Connie V.

            In one of your articles you mentioned potassium citrate pills should be for people with calcium stones and a urine citrate excretion below 400 mg/day despite the kidney stone diet. In this same article you state you understood you have one trial of the agent in people with substantially more urine citrate. As my urine citrate is considerably higher than the 400 mg/day, I was wondering if you have any information on that trial. Thank you.

            • Fredric Coe, MD

              Hi Connie, All the information on all the trials is in the articles. Here is the best of them. The citrate article is here. I believe one trial did include patients whose urine citrate levels seemed adequate, and I wondered at it. In fact only two citrate trials have been significant, they are in the first of the two articles. I hope this is not too vague an answer. Some trials were done before the relationship between stone risk and urine citrate was established. Regards, Fred Coe

      • Connie V.

        I did find these test results on vitamin D so I guess I did have this test. Hope this is what you need:

        Component My Value Standard Range
        Vitamin D, 25-Hydroxy 24 ng/mL 30 – 100 ng/mL

        • Connie V.

          I could not find any other vitamin D tests, so I did not have the 1,25 vitamin D test. Is this a test I should have?

        • Fredric Coe, MD

          Hi Connie, you do need a 1,25 D as the very hallmark of sarcoid hypercalciuria is a high level of that hormone. Over production of that hormone is the actual efficient cause of the high urine calcium. Speak with your physicians about measuring it. Perhaps they have done so. Regards, Fred Coe

          • Connie V.

            Thank you so very much for your replies, help, and suggestions. I have scheduled a test to measure 1,25 D, as it had not been done and I will follow your suggestion on discussing the urine sodium count with my physicians. I have tried to follow the 1500 mg of salt a day but I must not have been doing a very good job. I never add table salt to anything and do check labels of foods I buy. Guess I’ll have to do an even better job. Thank you again so very much for sharing your knowledge with us.

            • Fredric Coe, MD

              Dear Connie, Let me know. Regards, Fred Coe

              • Connie V.

                I received the results of my 1,25 D test. It was in the normal range: Vitamin D, 1,25-Dihydroxy 62 pg/mL 18 – 78 pg/mL

                So does this mean that my sarcoidosis is not what is causing my kidney stones but my high urine calcium level is what is causing them? Other than a low sodium diet (1500 mg) and drinking lots of fluids, do you have any other suggestions on lowering my urine calcium? I am already drinking lots of liquids and am on a low sodium diet, trying hard to maintain the 1500 mg a day, so I am frustrated and confused as what to do now. Also, I have osteopenia, so is it okay for me to take vitamin D supplements after all? Thank you!

              • Fredric Coe, MD

                Hi Connie, Although I am distant and not in touch with the details of your medical condition, I think that you may indeed have sarcoidosis but have high urine calcium because of genetic hypercalciuria. Sarcois raises urine calcium via pathological increase of 1,25D that suppresses serum PTH so you lose the calcium conserving properties of PTH while having the increases in kidney calcium receptor abundance and GI calcium absorption and bone turnover increase from the vitamin D. You have a normal PTH, high normal 1,25D, and therefore treatments that work for IH should work for you. This article considers all treatment options for common stone formers that I think you may well be. Please do not consider this a medical opinion as it falls quite short of that status and is merely a technical analysis of some numbers. Bring this note to the attention of your personal physicians; it is they who need to be responsible for your care, and they should do what they believe is medically proper with you. Regards, Fred Coe

              • Connie V.

                Sorry. I meant to ask if it is, therefore, not my sarcoidosis causing my high urine calcium as I understand it is my high urine calcium causing my stones. Thank you.

              • Fredric Coe, MD

                Hi Connie, your high urine calcium surely can cause your stones, and reducing it is a way to prevent stones. See my prior note to this one. Regards, Fred Coe

  2. Linda Mossman

    Greetings Dr. Coe.
    Your website has so much great information, I have been re-reading it numerous times. I am looking for a lab where I can send a stone to be evaluated. Do you have a recommendation?

  3. janisburns

    I’ve had repeated occurrences of calcium oxalate stones; and have been treated with K Citrate, and chlothalidone plus 50 mg Vitamin B for the past 10-15 years, mostly successfully. A recent bone density scan shows I have severe osteoporosis, and I’m only 62 years young. I’m supposed to research medication options and report back to my primary care physician. I have no idea if I have hypercalcemia…. Many osteo prevention medications mention they should not be taken if a person has this condition. Blood lab tests show calcium is in normal range, is this my answer? I’m at a loss on how to balance strong bones with a low calcium, low oxalate and low vitamin D diet. suggestions or advice welcome. Or are there questions you might suggest I ask during my follow up visit. thank you.

  4. D Clarke

    When I attempt to post a comment I get

    The requested URL was rejected. Please consult with your administrator.

    Your support ID is: 7339711674694711209

    • Fredric Coe, MD

      Hi, I am sorry. I am sending my programming colleague this material. I suspect our elaborate firewall did it. Thanks so much for sending this! Regards, Fred

      • fredric coe

        Apparently you used ” signs that the firewall took as an injection threat. Comments cannot have ” in them. Best, Fred Coe

  5. Annette Mullen

    I have just had a CT scan reveal several stones in both kidneys. The last 90 days, I’ve been on Prescribed Anti Fungal meds for a toe fungus. I developed a fever, UTI, my DR said, and was put on antibiotics 3 times, finally the CT scan, kidney stones. Is there any connection to fungal 90 day meds in regards to the production of stones, sorry, I’m sure it sounds absurd, but these are 2mm 3mm and one is 6mm, so recent SOMETHING was going on. Thank you1

  6. Jeanne Wudrick

    Can you recommend a major hospital to be tested at in Canada, as all we have here in Victoria, BC are local hospitals. Would UBC be okay, as they do a lot of research there of all types?

    • Fredric Coe, MD

      Hi Jeanne, UBC is an excellent place. I have no idea if they do stone prevention well but they will certainly be aware of what is happening internationally and are your best bet. Regards, Fred Coe

  7. Gina Silvio

    Question: I was put on Potassium Citrate to prevent kidney stones from one nephrologist. My new nephrologist says that potassium citrate is prone to cause uric acid stones and gout. Is this true? That is not what I read here or anywhere else. Is he mistaken? If so, why did one kidney doctor put me on K to prevent stones and the other wants to take me off of it? Thank you in advance.

    • Fredric Coe, MD

      Hi Gina, I do not know why your physician believes that potassium citrate will cause uric acid stones – it can not do that. As for gout, Likewise. I believe he/she simply did not make him/herself clear enough. You misheard. If not, that physician has the facts wrong. Regards, Fred Coe.

  8. Cheery Williams

    What a nice article! Awesome information and suggestion!
    I think Urinary Incontinence (UI) is world’s most unbearable and shameful diseases.
    Basically, this disease is more danger for the employer women. Like as Cherry 🙁

    • Fredric Coe, MD

      Hi Cheery, Thank you. I wish I could write a site for UI but alas it is beyond me. If you have stones as well, the article is very useful. In fact, it is useful for any patient in terms of helping their physicians help them. Regards, Fred Coe

  9. lee

    When taking the 24 hour urine test, should you eat and drink like you did when you first knew of the stone, to replicate what your urine was like then? Or should one continue to drink lots of fluids and eat in ways that prevent stones? Seems if you do the latter, you won’t really know what it was in your urine that caused the stone in the first place.

    • Fredric Coe, MD

      Hi Lee, What a fine question! To me the latter is right – do as you did, so one can tell what happened. Some do this, others changed their ways a while before coming in to see me, and would not want to go back. Usually there is enough wrong beside diet and fluids traces remain, but not always. But we have the history, too, so the original issues can be reconstructed. This area of medicine is very scientific and quantitative but people are not which makes things various. As to your question and what I would most like: Collect at first as things were, if possible. Regards, Fred Coe

  10. Michael

    Dr. Coe,

    Thank you for your highly informative website – the best I have sourced to-date. After a recent kidney stone, a metabolic work-up revealed the following results outside reference ranges:

    Calcium,U24Hr – 9.2 mmol/d – (Ref 2.5 – 7.5)
    Oxalate,U24Hr – 616 umol/d – (Ref 100 – 440)
    Urate,U24Hr – 4.7 mmol/d – (Ref 1.5 – 4.5)
    Urea,U24Hr – 644 mmol/d – (Ref 170 – 580)
    Sodium,U – 30 mmol/L – (Ref 40 – 200)
    Anion Gap – 14 mmol/L – (Ref 3 – 13)
    Phosphate,S – 0.6 mmol/L – (Ref 0.8 – 1.33)
    Vit D – 65 nmol/L – (Ref 75 – 250)

    All other measures were within reference ranges including pH,U (5.5), citrate,U24Hr (2.5 mmol/d), sodium,U24Hr (108 mmol/d), sodium (138 mmol/L), calcium (2.35 mmol/L) and potassium (3.9 mmol/L). Urine volume output was high/good (3.6L/d) and stone composition was calcium oxalate, mirroring that of stones from two previous episodes.

    A fit, late forties male with no major health issues or medication requirements, I workout regularly, consume 2.5+ L of liquids/day (primarily filtered water) and generally eat a healthy, balanced diet moderate in protein. Minor health challenges include common digestive upset (at meals), lactose intolerance and adverse affects on sleep due to increased fluid consumption.

    I have questions regarding the best prevention protocol and will be seeing a specialist next week to confer, however in preparation would greatly appreciate any thoughts or exchange of dialogue regarding my metrics – online or via email – to gain another perspective.

    Thank you in advance for your follow-up should you be able to accommodate a reply.

    • Fredric Coe, MD

      Hi MIchael, You appear to have a very high urine calcium despite a reasonable urine sodium of 108 mEq/day, a high oxalate excretion, and assuming a normal blood screening you would be the common idiopathic calcium oxalate stone former with genetic – idiopathic – hypercalciuria. I have reviewed the treatment trials for your kind of patient. You might check out this approach to prepare for your visit. Things should go well. Regards, Fred Coe

      • Michael

        Ironically, calcium,U24Hr was within reference range (6.9 mmol/d) in a full metabolic completed sixteen months ago after a calcium oxalate stone episode.

        A few questions in follow-up should you have time for a response:

        – is a bone density/disease test recommended for someone with idiopathic hypercalciuria?
        – is low Vit D a factor in stone production and should it be remedied via diet/supplementation?
        – with citrate supplementation, does the type matter (ie. potassium vs. magnesium vs calcium)?
        – are the benefits of lemon juice consumption (citric acid) akin to that of citrate supplementation?
        – are pro/prebiotics and digestive enzymes beneficial in influencing intestinal oxalate absorption?
        – if 200 mg/day), what is the conversion factor to mmol?

        Thank you kindly.

        • Michael

          The last point in the prior reply was cut-off and should have read:

          Finally, so that I may understand some of the measures noted in your website (eg. IH = >200 mg/day), what is the conversion factor to mmol?

          • Fredric Coe, MD

            Oh, I see; it is mg/day of calcium as the lowest detectable point of increased stone risk. Given the atomic weight of calcium as 40 mg/mmol that would be 5 mmol of calcium element. Regards, Fred Coe

        • Fredric Coe, MD

          Hi Michael, It is not rare for urine calcium to vary, especially with urine sodium or with diet. A bone density is a very good idea as bone disease is known to occur, Low vitamin D is not a cause of stones but is not healthy for bones and other organs and should always be corrected. Citrate supplementation is best with potassium, but is only important when needed – you have our writings on this. Lemon juice is a variable source of citrate; if the juice is too acid too much of the citrate molecules will be citric acid itself that confers no benefits. Probiotics etc are speculative as treatments and need trials. I do not know what the 200 mg/day means except perhaps diet total oxalate content; given an approximate molecular weight for oxalic acid of 90 mg/mmol 200 mg would be 2.22 mmol. Warm Regards, Fred Coe

          • Michael

            Can you kindly expand on your response, “lemon juice is a variable source of citrate; if the juice is too acid too much of the citrate molecules will be citric acid itself that confers no benefits.”? If lemon juice acidity varies, is there a level that is considered ideal and most beneficial? Lemon juice concentrate (eg. Realemon) is said to provide 1.1 g of citric acid per ounce (versus fresh lemon juice at 1.44 g/oz) and according to the FDA, lemon juice from concentrate must have “a titratable acidity content of not less than 4.5 percent, by weight, calculated as anhydrous citrus acid.” Would lemon juice from concentrate be considered a more standardized level of acid content and therefore a better alternative than fresh lemon juice? If so, can high consumption pose any health risks from the added preservatives (ie. sodium benzoate, sodium metabisulfite and sodium sulfite). From what I have researched, ingesting 4 ounces per day of fresh lemon juice appears a good adjuct to diet changes. Thank you kindly.

          • Michael

            Can you kindly expand on your response, “lemon juice is a variable source of citrate; if the juice is too acid too much of the citrate molecules will be citric acid itself that confers no benefits.”? If lemon juice acidity varies, is there a level that is considered ideal and most beneficial? Lemon juice concentrate (eg. Realemon) is said to provide 1.1 g of citric acid per ounce (versus fresh lemon juice at 1.44 g/oz) and according to the FDA, lemon juice from concentrate must have “a titratable acidity content of not less than 4.5 percent, by weight, calculated as anhydrous citrus acid.” Would lemon juice from concentrate be considered a more standardized level of acid content and therefore a better alternative than fresh lemon juice? If so, can high consumption pose any health risks from the added sulfite preservatives. From what I have researched, ingesting 4 ounces per day of lemon juice appears a good adjuct to diet changes. Thank you.

            • Fredric Coe, MD

              Hi Michael, Reasonable issues, but the information is not there for us. It is the pH that determines the fraction of citrate as the anion vs citric acid. Lemon juice mostly has a low enough pH that most of the citrate is citric acid. The titratable acidity is of no value as it is a function of the total proton receptor molecules in the solution – not just citrate – and the pH. Concentrate is equally unknown. One needs the total citrate and pH of the finished beverage to figure out the citrate availability. Regards, Fred Coe


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