My Lab Report


To me at least, the lovely Blue Door watercolor by Andrew Wyeth is simplicity created by studied art.

Take a look at your lab report(s) and answer these questions. If you have two 24 hour urine collections this time answer from the more abnormal in every case. Here is help for reading these if you are confused. Here is more help.

But keep this in mind. I assume here you have personal physicians; that you have been screened properly to rule our systemic diseases as a cause of your stones; and that your other health issues are being looked after by your physicians. This kind of simplified approach is nice for otherwise healthy idiopathic calcium or uric acid stone formers. Others may need much more.

Section One: Initial Evaluation

Answer the questions.

The blue responses are actions you should take

  1. Is my urine volume less than 2.5 liters?
    1. No – It is high enough
      1. Was my collection representative of my usual life or was I showing off
        1. Representative
        2. Showing off – I should check another urine collected during my usual life
    2. Yes – Raise my fluid intake to 2.5 liters: 2.5 – my volume = my increase in fluids
  2. Is my urine calcium above 200 mg?
    1. No – It is not high enough to increase risk of stones
    2. Yes – It is high enough to increase risk of stones
      1. Is my urine sodium above 100 mEq (1500 mg)
        1. Yes – Lower my sodium intake to below 100 mEq (2300 mg); 1500 mg is ideal
        2. No – My sodium intake is not high
      2. Do I eat a lot of sweets – sugared foods?
        1. Yes – Reduce my sugar intake as it increases urine calcium
        2. No – My sugar intake is not high
      3. Do I eat at least 1000 mg of food calcium daily?
        1. Yes – People with hypercalciuria need diet calcium for their bones – continue this diet
        2. No – I need to eat at least 1000 mg of diet calcium daily
  3. Is my urine oxalate above 35 mg?
    1. No – My urine oxalate is not very high
    2. Yes – My urine oxalate is high enough to increase risk of stones
      1. Reduce high oxalate foods using the lists on this site
      2. I need to eat at least 1000 mg of diet calcium daily
      3. Is my urine oxalate above 80 mg?
        1. No – I can try diet to lower my urine oxalate
        2. Yes – My urine oxalate is so high my physician needs to review the matter and decide what to do
  4. Is my urine citrate below 400 mg?
    1. Yes – It is low enough to raise risk of stones
      1. Is my blood potassium low or do I take diuretics?
        1. Yes – My physician needs to provide potassium supplements
        2. No – Use beverages that provides supplemental alkali to raise my citrate
    2. No – It is not low enough to raise risk of stones
  5. Is my urine pH below 5.5
    1. Yes – My urine pH is low enough to pose a risk for uric acid stones
      1. Is my uric acid supersaturation above 1?
        1. No – Is my urine volume high?
          1. Yes – High volume is protecting me against uric acid stones
          2. No – Uric acid may be crystallizing; Raise my fluid intake to 2.5 liters: 2.5 – my volume = my increase in fluids
        2. Yes – Use beverages that provides supplemental alkali to raise my urine pH
    2. No – My urine pH does not pose a risk of uric acid stones

Select and print this list

Circle the actions you need to do and pin the list up where you will see it

  1. I should check another urine collected during my usual life
  2. Raise my fluid intake to 2.5 liters: 2.5 – my volume = my increase in fluids
  3. Lower my sodium intake to below 100 mEq (2300 mg); 1500 mg is ideal
  4. Reduce my sugar intake as it increases urine calcium
  5. I need to eat at least 1000 mg of diet calcium daily
  6. Reduce high oxalate foods using the lists on this site
  7. My urine oxalate is so high my physician needs to review the matter and decide what to do
  8. My physician needs to provide potassium supplements
  9. Use beverages that provides supplemental alkali to raise my citrate
  10. Use beverages that provides supplemental alkali to raise my urine pH

Get a follow up 24 hour urine test when all of the actions are in play

Section Two: Follow up Evaluations

Here is what to do when you have a follow up test

First answer the questions in Section One.

Then answer the questions here in Section Two

The blue responses are actions you should take

  1. Do I know what my stones have been made of?
    1. Yes – Look at the supersaturation(s) related to your stone(s); call these your relevant supersaturations
    2. No – All three supersaturations may be relevant
  2. Have all of my relevant supersaturations fallen by half?
    1. Yes –
      1. Am I still forming new stones
        1. No – Stay on my treatment and get another follow up in one year; if new stones form get it sooner
        2. Yes – Am I sure this 24 hour urine reflects my usual life?
          1. Yes – I may need medications; see my physician
          2. No – Get another 24 hour urine within the next 6 – 12 weeks
    2. No – Go back over the blue actions in section one
      1. Is my uric acid supersaturation one that has not fallen by half?
        1. Yes
          1. Is either blue action 2 or 10 in section one above suggested?
            1. Yes – Do the blue actions suggested in section one and obtain a new 24 hour urine
            2. No – Raise my fluid intake to 3 liters a day and obtain a new 24 hour urine
        2. No – Either my calcium oxalate or calcium phosphate supersaturation has not fallen
          1. Are any of blue actions 2 – 9 in section one suggested?
            1. Yes – Do the blue actions suggested in section one and obtain a new 24 hour urine
            2. No – Raise my fluid intake to 3 liters a day and obtain a new 24 hour urine

Select and print this list

Circle the actions you need to do and pin the list up where you will see it

  1. Stay on my treatment and get another follow up in one year; if new stones form get it sooner
  2. I may need medications; see my physician
  3. Get another 24 hour urine within the next 6 – 12 weeks
  4. Go back over the blue actions in section one
  5. Do the blue actions suggested in section one and obtain a new 24 hour urine
  6. Raise my fluid intake to 3 liters a day and obtain a new 24 hour urine

71 Responses to “My Lab Report”

  1. Ken

    Hi Dr. Coe, would welcome your thoughts on the following from Litolink which I received today; I starred the items that are listed as outliers (will have a followup appt with my urologist in another 6 weeks) – Have had stones for about 7 years or so, with the frequency increasing over the past 1-2 years

    Volume 3.7
    SS CaOx 4.24
    Urine Calcium 135
    Urine Oxalate 91*
    Urine Citrate 829
    SS CaP 0.64
    pH 6.954*
    SS Uric Acid 0.09
    Urine Uric Acid 1.177*

    Dietary Factors:
    Na 150
    K 194
    Mg 117
    P 0.934
    Nh4 55
    Cl 199
    Sul 45
    UUN 18.82*
    PCR 1.5*

    Normalized Values:
    Cr24 2995
    Cr24/kg 32.2*
    Ca24/Kg 1.5
    Ca24/cr24 45


    • Fredric Coe, MD

      Hi Ken, The obvious high oxalate needs attention. Low calcium diet is a common cause. I notice a very high urine potassium but it is not potassium citrate because urine NH4 is higher than sulfate. Do you take potassium chloride or vast amounts of fruits and veggies? These are just thoughts – data alone do not get you very far. Feel free to share them with your urologist. Regards, Fred Coe

  2. David Taylor

    Dr. Coe;
    Could you give me your opinion on my 24 hour urine results. A little history: I am 59 years old and have had Calcium Oxolate stones since the mid 1980’s. At that time I was told I have MSK in my left kidney..all of my stones come from the left kidney, right one never shoes any on scans. In the late 1990’s, I was diagnosed with Ulcerative Colitis. I’ve only had one “flare-up” since then and it is easily brought under control with medicine. I currently take no medicine for this. Here are my results. Thanks.
    Volume 3.09
    SS CaOx 3.18
    Urine Calcium 248
    Urine Oxalate 24
    Urine Citrate 679
    SS CaP 0.44
    pH 5.976
    SS Uric Acid 0.41
    Urine Uric Acid 0.590
    Dietary Factors:
    Na 165
    K 55
    Mg 79
    P 0.772
    Nh4 45
    Cl 181
    Sul 39
    UUN 9.65
    PCR 1.0

  3. Justin

    Sorry, slight glitch in my comment from a few minutes ago: the end of the paragraph after the first batch of numbers should read “With SS CaOx under 3.0, Ca 24 of 51 and Ox 24 of 30, isn’t it a bit ridiculous that I would consistently form these large crops of CaOx stones? I know that crystal formation becomes possible at any SS over 1.0, but these numbers seem highly unusual for such a prolific stone former as I am.” Alas, the script that processes the comments doesn’t seem to be able to deal with less than/greater than signs.

    • Fredric Coe, MD

      Hi Justin, I have already mentioned one possible way you might have formed stones. Another is periodic very low urine volumes, or perhaps spells of vomiting or diarrhea. Consider if these are possible. You are right = something raised supersaturations, created stones, and is gone. Regards, Fred Coe

      • Justin

        Many thanks for your consideration and suggestions. I’ll respond to both of your comments here, and will try to keep it brief. The MSK suggestion is interesting, and I will follow up on that, but at a glance it seems that in a case such as mine the only recommendation for it would be to keep on top of fluid intake as I’ll already be doing, so even a positive diagnosis there wouldn’t necessarily seem to impact the approach to treatment. The Litholink report briefly raised the spectre of RTA due to the Cit 24 and pH, but it seemed a bit dubious, so I am heartened not to see you ringing any major alarm bells there.

        As far as the nutrition goes, I do have some work to do on that, and I can confirm that I do tend to get inadequate diet calcium as well as relatively little protein. I know I should correct this, but I didn’t realize it could contribute to stone formation even in the absence of elevated urine calcium levels–are you saying that excessively low urine calcium actually increases stone risk? If so, I’d appreciate if you could point me toward where that might be discussed, especially as I can’t help but feel concerned that any correction of the low urine calcium will correspondingly raise my supersaturations and therefore increase my stone risk. You’re also quite right about the low body fat, but I can’t seem to do much about that, as I’m just naturally very skinny, and my doctors have never thought there was any pathology there. I don’t generally tend to get spells of vomiting or diarrhea, and my urine volumes hardly ever fall very much below the 1.5 liters seen on the low-flow day of my Litholink test, though I can say that in the periods leading up to stone recurrences, my urine volumes are probably tending to stay around the lower end of that range for weeks or months on end. Given the numbers I’ve shown you, could that be enough to explain the recurrences, or must there also have been some other factor spiking supersaturations beyond the levels seen on the low-flow day of the recent test?

        The Litholink report flagged my low citrate, high pH, low magnesium, and low phosphorus as stone risk factors. In addition to keeping my fluid intake on track and making general dietary improvements, am I likely to need to place any special emphasis on correcting any of those? And one final question: given that my oxalate levels seem perfectly fine, am I free to select relatively oxalate-rich foods as I make the dietary modifications? It would be nice to have that additional freedom as I tackle the process of improving my nutrition. Thanks once again for all your help!

        • Fredric Coe, MD

          Hi Justin, This is becoming complex, and I lack sufficient knowledge of your actual medical situation to go into further detail. Please feel free to share any of my remarks with your physicians, and they will do with them what they wish. But only they can actually take responsibility for your care and I fear becoming a nuisance to them or, worse, an inll informed spectator. Regards, Fred Coe

          • Justin

            Understood. Thanks in any case for taking the time to consider my situation, and of course, for everything else you do!

  4. Justin

    Dr. Coe and colleagues, I must first extend my deepest thanks for all of your stunning work throughout this website. It is truly a one-of-a-kind resource for patients (and probably not a few doctors!), and your passion for the subject shines through on every page. From the bottom of my heart, thank you. I apologize in advance for the length of this comment; much of it consists of test results that you may skip or skim as appropriate, and I have tried to keep the rest as brief as possible.

    I am a patient presenting with a recurring CaOx stone condition, which has troubled me on and off for a decade or so now. I produce stones in both kidneys, but particularly on the right; they seem to form quite slowly, tend to be smooth and round, and always pass while still relatively small. Most of them don’t seem to cause any pain for some reason, and I’ve passed at least a few as large as 3-4mm without even noticing. Unfortunately, every so often my luck runs out and I experience the typical pain and difficulty while passing one, usually as it nears the UVJ. This has landed me in the ER multiple times, most recently last month, and I have resolved to get serious about prevention to ensure that there will not be a next time. As such, I recently had my first 24-hour urine panel done (the “2, 24 hour Urine Panel” from Litholink).

    The reason I make this humble request for a few moments of your attention, rather than satisficing myself with the trove of expert knowledge offered throughout the site, is that my Litholink results are a bit puzzling, and my doctors and I aren’t entirely sure what to make of them–I gather I’m a bit of an unusual case. I can think of no obvious reason for this: I’m a 32-year-old male in generally fine health, and my medical history is blessedly devoid of anything interesting. I have had occasional problems with IBS, my liver is mildly fatty yet appears otherwise healthy, and I seem to be deficient in Vitamins B12 and D, but that is virtually the entire extent of my health concerns apart from the kidney stones. I certainly have never had any other detectable renal or urological issues.

    The stones come in clusters, with years sometimes passing uneventfully and with no detectable stones on my ultrasounds, then a substantial crop suddenly appearing all at around the same time, likely occasioned by lifestyle-related shifts in daily urine volume. The stone that most recently landed me in the ER was 3x2x2mm, 95% Whewellite and 5% Apatite, from the right kidney; as usual, the resulting CT scan revealed that I currently have at least two other stones in that kidney, though these are thankfully “punctate” at present. Some weeks after passing that stone, I did my Litholink urine test, with the following results. (Note that, at the instruction of my urologist, I spaced the two 24-hour collection periods about a week apart. I think I did a pretty good job of capturing what has recently been my usual behavior with respect to fluid intake and everything else; as you’ll see, the fluid intake fluctuates quite a bit, and as it so happened, the first collection period captured a very typical low-flow day for me, whereas the second collection period captured a typical high-flow day. This wasn’t planned as such, but should prove instructive. Obviously, I have taken care to ensure that there are no typos and that the numbers are presented in the correct order on each line.)

    Vol 24: 1.48, 2.89
    SS CaOx: 2.95, 0.65
    Ca 24: 51, “less than 43” (too low to measure!)
    Ox 24: 30, 32
    Cit 24: 370, 381
    SS CaP: 0.48, 0.10
    pH: 6.412, 6.932
    SS UA: 0.28, 0.05
    UA 24: 0.468, 0.457
    Na 24: 136, 114
    K 24: 33, 36
    Mg 24: 48, 40
    P 24: 0.591, 0.433
    Nh4 24: 25, 22
    Cl 24: 134, 109
    Sul 24: 17, 11
    UUN 24: 4.46, 3.75
    PCR: 0.7, 0.6
    Weight: 54 Kg
    Cr 24: 1490, 1553
    Cr 24/Kg: 27.4, 28.5
    Ca 24/Kg: 0.9, “less than 0.8”
    Ca 24/Cr 24: 34, “less than 28”

    The results from the high-flow day are, of course, quite heartening–the supersaturations in particular can be taken to mean that I would be able to avoid ever forming any further stones simply by maintaining that level of flow on a consistent basis, yes? That would seem to be cause for celebration, and perfectly sufficient basis for a wonderfully simple treatment plan consisting of nothing other than maintaining a daily urine volume in the neighborhood of 3 liters. However, my doctors and I find the numbers from the low-flow day puzzling, and possibly worrisome. With SS CaOx 1.0, but these numbers seem highly unusual for such a prolific stone former as I am.

    I can’t help but wonder what strange thing my body is doing to cause such an unusual result. If it’s something benign or merely idiosyncratic, that is one thing; however, I’m starting to wonder whether it may be a sign that something else demands correction in addition to the urine volume. If anything jumps out at you based on the above results, I would really love to know your thoughts. I also wonder whether this is a sign that I should more thoroughly revisit the possibility of systemic diseases, which my doctors have never considered likely enough to justify more than a somewhat cursory investigation. If it helps, I do have a serum metabolic panel, taken during the recent ER visit and processed at the hospital lab. Here are the numbers:

    Serum Sodium: 138
    Serum Potassium: 3.6
    Serum Chloride: 103
    Serum Carbon Dioxide: 27
    Serum Anion Gap: 8
    Serum Blood Urea Nitrogen: 8
    Serum Creatinine: 1.13
    Serum Glucose: 94
    Total Serum Calcium: 9.4
    Total Serum Protein: 7.3
    Serum Albumin: 4.3
    Total Serum Bilirubin: 0.9
    eGFR: 86 (non-African-American)
    Serum Alkaline Phosphatase: 51
    AST/SGOT: 25
    ALT/SGPT: 35
    Serum Lipase: 133

    In addition to the above, another recent blood test found a serum uric acid of 6.9. I don’t have serum phosphorus, magnesium, or pH numbers, but do have a variety of other recent blood measurements; please ask if there are any you’d like to know, and I will provide them if that might help.

    Thank you so much for everything, and I do apologize again for the length of this comment. If you could offer even just a few quick thoughts on my situation, that would go quite a long way indeed toward helping me feel that I may finally be able to get this all under control. Best regards to all of you!

    • Fredric Coe, MD

      Hi Justin, Your labs show a pathologically low urine calcium and I suspect inadequate nutrition. Your protein intake is low, so is your urine phosphorus and sulfate. Ask you physician to consider limited medullary sponge kidney – affecting only a part of the kidney. Likewise, I suspect inadequate calcium intake. Your creatinine/kg body weight suggests very low body fat stores – is there an eating problem here. These are just thoughts for you and your physicians to consider. Regards, Fred Coe

  5. Stephanie

    Will adding in the recommended beverages to increase citrate affect urine pH? My urine citrate hovers Just below 400 so I would like to raise it some but my urine pH has been at or just above 6.2 on my last few Litholink reports.

    • Fredric Coe, MD

      Hi Stephanie, When citrate is low be sure and think about all causes: Low potassium inadequate servings of fruits and veggies- 5 or more a day, and GI disorders. If you need more citrate, be sure you know why. Ask your physician or look at your labs. Is your supersaturation now half or less of what it was before you began treating yourself; I mean supersaturation with respect to the crystals in the stones you form. If it is, 400 mg/day of citrate is just at the point where stone risk begins. Regards, Fred Coe

    • jharris

      Hi Stephanie,

      It might increase your urine pH a bit, but it is important to get your citrate levels up. If you have high pH levels, but your urine calcium level is within normal limits and you are drinking enough fluids to produce 2.5 liters of urine you will be in good shape. Hope this helps-


  6. Patti

    I got my results back from Litholink on my 24 hour urine. I am confused as to whether or not I should be taking Calcium. My urine volume was very low at 0.69, SS CaOx is 14.70, not a typo. Urine calcium is 127. Urine oxalate is 38. Urine citrate is 958. SS CaP is 3.95. Urine ph is 6.752. SS uric acid is 0.28. Sodium is 120. The Nurse Practitioner called today and said to just drink more fluids. I am thinking based on these results that I should be on a low oxalate diet and increase fluids. I am not sure if I should add OTC calcium or not. What do you think based on these results. I might add that I am an RN and have been a nurse for 23 years. I am 50 years old and have had 8 kidney stones over the last several years, approximately every other year. Thanks for the reply and your website is great.

    • Fredric Coe, MD

      Hi Patti, Your urine volume is surely a serious liability. Calcium and citrate are not risk factors in you – you discovered that from the article. Urine oxalate is a bit high. You do not mention the type of stone you form, but your CaP SS is actually as bad as your CaOx SS: It takes about a SS of 4 – 5 to produce CaOx stones but for CaP anything above 1 will do. Like everyone who has a skeleton you should have 1,000 to 1,200 mg of diet calcium daily preferably from food. I would do that before worrying about an oxalate list. Here is my best on that. Get another 24 hour urine on fluids – lets do 2.5 liter urine or 3 liters fluid intake – and high diet calcium. Be sure and have the high calcium with the meals that will have substantial oxalate – the larger meals. Supplements are alright but food calcium is better. IF calcium and fluids are not enough to bring the SS down, then lower diet sodium – below 100 mEq preferably 65 mEq – the present US ideal intake. Regards, Fred Coe

  7. James

    Hi Dr. Coe, someone else asked pretty much the same exact question I had, but I didn’t see an answer. I’ll just say it like they did and hope you can please clarify it. Thanks much
    I am trying to “understand my “LithoLink” 24-hour urine report, which has my pH of 6.491 indicating “increased risk for stone formation”, with a reference range of 5.8-6.2. I thought that the higher the number, the more alkaline, the less stone formation risk, with 7 the point of neutrality–so I thought I might need to become more alkaline. Thanks again for all your work and your help. “

    • Fredric Coe, MD

      Hi James, There are two main calcium stone types – calcium oxalate and calcium phosphate. The former are indifferent to pH; the latter arise when pH is increased because the phosphate component takes on 2 negative charges with higher pH and they are required for binding with calcium. I do not know where you were told a higher urine pH prevents stones, it does not. The reason potassium citrate is used is to increase urine citrate, and an unfortunate byproduct is a rise of pH. I hope this is helpful. Regards, Fred Coe

      • James

        Thanks Dr. Coe. My 24 hr. urine test was done by the company “Litholink” and ordered by my urologist. Urine pH was one of the many things tested, and on their scale of ‘decreased/increased risk for stone formation’ their reference range for pH is 5.8-6.2. My particular pH was 5.0, and according to their graph, that increases the risk of stone formation. Their written recommendation for my ‘very low urine pH’ is to treat with potassium citrate, to raise it. So doesn’t that mean, according to them anyway, that a higher pH will lower the risk? (My stone was 90% calcium oxalate and 10% uric acid.)

        • Fredric Coe, MD

          Hi James, I wrote that Litholink report algorithm with John Asplin. The low pH can cause the uric acid component in your stone and treatment with potassium citrate is indeed a good idea. The increase of urine citrate – if any – will possibly reduce for calcium oxalate as well, but there may be other factors for that part such as urine calcium, oxalate, or volume. If so they all need treatment. Regards, Fred Coe

  8. google

    My coder is trying to convince me to move to
    .net from PHP. I have always disliked the idea because of the
    costs. But he’s tryiong none the less. I’ve been using Movable-type on various
    websites for about a year and am nervous about switching to another platform.
    I have heard very good things about
    Is there a way I can transfer all my wordpress posts into it?
    Any help would be really appreciated!

    • Fredric Coe, MD

      Hi Bernard, I have no experience with this. I did a small site on Google and like it, but it is personal and does not have the utilities this one needs. Regards, Fred Coe

  9. Wayne Lee

    I have experienced over 10 CaOx renal stones since 1970. Two would not pass and were treated surgically. Had left ESWL last week for 2 stones (5.4 & 7.2 mm) that were about 3 & 5 mm size 4 years ago. I have been on a low salt, low oxalate and increased calcium diet for years. I have the results from my 24 hr urine collected before the ESWL and the lab report on the stone that passed in August. My urologist has reviewed the urine results and does not recommend any change to my treatment plan. How can I arrange a personal consultation for Dr. Coe the review and comment on the results? I would prefer a reply to my email address. Thanks.

  10. Kelly Stanley

    Hi Dr. Coe,
    I just got my 24 hr urine test back. My Doc prescribed hydroclorothiazide 12.5 mg once a day. I am apprehensive to take medicine. He also said reduce sodium and increase fluid. I enclosed some of the results. Is there anything else I should be doing to reduce my stone risk ? Thanks,Kelly
    Ph 6.372
    24 Hr Citrate 963
    24 Hr Oxalate 36
    24 Hr Uric Acid 0.691
    24 Hr Calcium 284
    Urine Volume 1.78
    Supersaturation Caox 7.77
    Supersaturation Cap 2.58
    Supersaturation Uric Acid 0.37

    • Fredric Coe, MD

      Hi Kelly. Your doctor seems quite reasonable – what was the urine sodium?? You are hypercalciuric, and it would be good to raise your diet calcium intake to 1,200 mg and drop the sodium intake below 2000 mg, and see what your SS and urine calcium do. The drug would work even better if you lower your sodium and refined sugar intakes and perhaps might not even be needed. The urine oxalate may fall a lot with the high calcium intake. The drug is a reasonable choice, and if diet calcium sugar and sodium changes and lots of water are not enough you may well want to use it. The goal is for those supersaturations to fall at least by half, and your urine calcium to go below 200 mg/d and oxalate below 25 mg/d so you have a clear goal. Regards, Fred Coe


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