24-Hour Urine Collections: Why and How

Jill jpegWhy

You have a kidney stone episode and your doctor asks you to collect your urine for 24 hours. Why oh why is this being asked of you? Isn’t it dreadful enough that you just had a kidney stone?

The only way to find out WHY you are forming kidney stones is to complete a urine collection.

The test results will tell your doctor how saturated your urine is with stone making crystals.

The more saturated your urine is, the more likely you are to form new stones.

Some clients have come to me and said, “Why do I need to do a urine collection if the doctor removed my stone and had it analyzed?”

A stone analysis may tell you what type of stone you made, but there are many different reasons you may have made that type of stone.

Figuring out your prevention plan is very complicated, and without a urine collection it is nearly impossible.

Figuring out all of the details behind urine collections can be exhausting. I just released a course called The Kidney Stone Prevention Course to help you understand how to implement your physician’s prescribed treatment plans.


One Day or Two Day Collections?

When you do your first collections, the ones your treatment is going to be based on, it is wise to do two: Two 24 hour urine collections.

Before you start pulling your hair out, let me tell you why.

What you eat and drink during your collection is going to be represented by your test results. If you do your collection on your birthday, you may be celebrating, drinking, eating foods you don’t usually eat and this will not represent a “normal” day for you.

If you do two collections, your test results will show a better picture of what you are eating and drinking.

Sometimes I see a two day collection and the day to day results are so very different they enable me to ask some important questions. For example, “The sodium levels in your urine were very high on your first collection, did you go out to eat that day?”

When I worked at Litholink Corporation we would tell patients to collect their urine on a weekday and a weekend day.

We requested the collection be completed this way because typically what we eat during the week is not what we eat during the weekend.

This way the lab results would show the difference between eating and drinking habits and we could offer better treatment suggestions to the doctors on the lab report.


Always Drink and Eat Normally

Many patients don’t want to hear their doctor scold them for not drinking enough so when they do their urine collection they drink and drink and drink. This is not what they usually do. Some already know they were eating badly and made some big changes so their tests would look better.

Why am I going to call you out on this? Am I just a pain in the neck?


Cheating on Your Collection Days Will Not Help

If you drink more than you usually do or eat differently than you usually do, your doctor will base your treatment plan on what you did for those days.

You want your treatment plan to be based on what you usually did when you formed stones so that changes you make will lessen your chances of making more stones.

Suppose you already know you should drink more water, and you do it during your collections. You never did it before, when your stones were forming. Your doctor sees that you’re drinking 4 liters of water a day (you wanted to impress him or her).

S/he will be impressed and assume that low fluids were not and will not be your problem.

But, maybe low fluids were your problem. You won’t know and neither will your doctor.

So what?

No one, including you, will make fluids a priority and you may well forget to keep showing off.

Then what?

Maybe nothing else was wrong except low fluids, and that was gone for the moment – when you did the tests.

Maybe the fluids have already fallen back to your original low levels.

Your doctor will not be able to offer you any help, or worse, may tell you something generic like “avoid all green, leafy vegetables”. I don’t want anyone avoiding green, leafy, veggies if they don’t have to.

I tell clients, “if you drink gin all day then please do that during the test”.

If you don’t drink much water, please do as you normally do.

Getting on the right treatment plan is imperative in preventing new stones from forming. The only way to get on the right treatment plan is to eat and drink as you normally do on the days you are collecting your urine.


Diet Changes Before Collection Begins

Some of you were told to change your diets before doing the urine collection and wind up doing the collection while on your new diet.

This will NOT help.

You want your results to show what you did while you were making stones. For the day(s) you are asked to collect your urine, eat as you did before you knew you had a kidney stone.

Then go back to doing what your doctor told you to do or what s/he tells you to do after the test results are available.

Don’t Collect During Holidays

Many people will want to do their collection on the holiday because they are off work. If you are like me, you eat differently on holidays than you do on non-holidays.

Thanksgiving is not representative of how you normally eat, so this is not the time to do your collection.

Remember, since your results will show what you ate for that particular day, a treatment plan based on holidays will not be useful to you. Your doctor may tell you to go on certain diets that you do NOT have to go on.

That would not be helpful at all!

Make Time to do the Urine Collections

I completely understand that doing a urine collection is a total pain in the neck. It is annoying and nothing you want to do.


There is nothing quite as bad as having a stone attack. If you have to weigh one against the other, doing a urine collection is the clear winner.

Find the time. It’s worth it.

Occupation Need Not be a Barrier

I have had pilots, truck drivers, surgeons, salespeople, and teachers all find the time and make collections while at work. Whether or not it is possible depends on a lot of circumstances, but doing it on the job is the ideal for one of your two days.

Some of you will not be able to bring the collection jug to work.

Perhaps you might have to take a day off from work.

If you do take a day off from work, please drink and eat as you normally would on a work day.

If you do a two-day collection, remember to do one on a weekend so your doctor can see how it differs from a weekday.

Questions About Your Collection

Once you receive your urine collection, please read all instructions on how to complete it.

If you have any questions, call the place of business you received your supplies from and ask them all the questions you may have before starting the collection.

It is dreadful when you have to re-do a collection because you didn’t do it the way they wanted you to.

Follow-up Collections

Once you do your initial 48-hour urine collection, the doctor will go over the results with you.

From those results, you will be told to do certain things that will help prevent stones in the future. You may be told to go on medications, drink more water, change your diet, or all three.

Four to six weeks after you have incorporated all the changes your doctor has prescribed for you, your doctor SHOULD ask you to do a 24-hour urine collection to make sure those changes are working for you.

If you don’t do a follow-up, how will you know if your treatment plan is working?

If your doctor doesn’t order a follow-up, ask for it.

You should expect your doctor will contact you about your results and make whatever changes are needed to get you the best possible prevention.

Annual 24-Hour Collections

Our urine chemistries change over time. It is prudent that you complete a yearly collection to ensure your treatment plan is still working for you.

Partly urine chemistries change because we are getting older, or have developed some new disease condition.

Diets change even if we are unaware of the changes because they occur slowly.

We gain or lose weight which can affect urine chemistries.

Our habits change: We give up or get a health club membership, or start running.

A Final Thought from Jill

Clearly now, you can see how important it is to complete urine collections.

I want you to know that I don’t ask you to see the importance of doing these darn collections without having compassion and empathy that you have to do them.

I know they are not convenient, nor are they fun.

Just keep in mind that if you don’t complete a urine collection, you will not know why you formed stones and will most likely keep right on forming them.  I want to keep you away from that scenario.

Prevention is always our best defense. Completing your collections is a pretty benign way to keep stones at bay.

Return to Walking Tour about Supersaturation

Figuring out all of the details behind urine collections can be exhausting. I just released a course called The Kidney Stone Prevention Course to help you understand how to implement your physician’s prescribed treatment plans.


65 Responses to “24-Hour Urine Collections: Why and How”

  1. Janene Solis

    I am waiting for my 24 hr urine collection kit from Litholink. Went to my PCP this morning and it looks like I have a UTI. Awaiting lab results and hope to have them in 48 hours. Do I have to wait now to do my 24 hour urine test till after the antibiotics are done? I want the best results of course! Also, my blood serum shows that I have high uric acid (8.3). Do I also wait till after the urine collection to drink lemon in my water? If I understand correctly, I should eat like I used to eat before the stones (gone now litho July 2017). A nice spinach salad?

    • Fredric Coe, MD

      Hi Janene, I would wait. Don’t make changes now, wait for the test results to avoid confusion. Why would anyone drink lemon anyway unless their urine was low in citrate. Even then there are better ways. Regards, Fred Coe

  2. Johnathan

    Hey I was wondering if marijuana will show up on the results from the 24 hour urine collecting?

    • Fredric Coe, MD

      Hi Johnathan, I do not know. No one tests these panels for drugs, so it would not be found in the course of stone testing. I suppose if someone wanted to look they might find it. Regards, Fred Coe

  3. Zara D

    Hi my 14 month old has just completed 3x 24 hour urine collections using a catheter and drain inher kidney. I changed her nappy once a day and noticed the nappy was slightly damp like the catheter may have leaked a tiny bit. She is only a baby so its nearly impossible to get every drop but im sure we got 99% of it. Will this make a huge difference to the results? I dont want to make her do it all over again. She was super uncomfortable 🙁

  4. Irene

    Is this also used by employers for drug screening?

    • jharris

      Hi Irene,
      No, this is not used for drug screening. When you test urine for drugs it is a “pee in a cup type of thing”. A urine collection for kidney stone work up is collecting your urine for 24 hours.


  5. Kearstin

    Hello I’m an 18 year old female, I’ve recently went to my urologist with 6 stones in the right kidney and 5 in the left. I’ve had kidney stones since I was 13. My urologist did a comprehensive metabolic panel and PTH test and that all came back normal but I have to do a 24 hour urine test. What would be shown in the urine that wouldn’t be in the blood? Thanks

  6. Don

    Hello. ..
    I’m suffering of uti on and off for 8 months if not mistaken…. drinking water, antibiotics didn’t di much work. … a couple of doctors discovered I have deposits mostly on right kidney by ultrasound. .. and I think the right ureter is inflamed but I don’t know since it hurts often in one point above ovary it might be a stone. . it’s frustrating to live in pain with not much of offering a solution (drink water take a few pills and you’ll be fine. … not really my reality)
    anyway I’m going to do a few tests and this 24 urine test as I read will help with my condition. .. so please can you help in my case what elements need to be checked such as calcuim uric acid etc

  7. kim

    I’m doing the 24 hour pee test if I have cancer or a stone will they find it. I’am a smoker that’s the only bad thing I do besides drink coffee and tea. there telling me not to have anything like that while i’m doing my test so will smoking screw up my test.

    • Fredric Coe, MD

      Hi Kim, urine testing will not identify cancer unless it involves special cytology. Smoking is not an issue. Cancer is detected with other means than 24 hour urine collections. Regards, Fred Coe

  8. Maria

    Hi Im doing a 24 hour urine collection (catecholamines, metanephines, vma, hva and 5hiaa) but i drank diet coke, can i still collect my urine?

  9. Kara

    So I started my one day collection the night before on accident… Will this affect my results?

    • jharris

      Hi Kara,

      You must collect for a 24 hour period. When you start that 24 hour period is up to you.

      Hope this helps-


  10. Reese

    I have a 24 hour urine that starts in the morning. Is it best to not have any alcohol, like wine before the test?

    • Fredric Coe, MD

      Hi Reese, It is best to do what you usually do so the sample will represent your real life. regards, Fred Coe

    • jharris


      If you normally drink alcohol, then it is fine. If this is something you don’t usually do then save it for after the test. You want to see what a normal eating and drinking day looks like on your report.



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