This information explains how to collect and store your urine (pee) for your creatinine clearance test.
About your creatinine clearance test
Creatinine is a substance in your blood. It’s normally filtered from your blood by your kidneys and cleared (removed) from your body in your urine.
A creatinine clearance test compares the amount of creatinine in your blood to the amount in your urine over a 24-hour period. This shows how fast your kidneys clear creatinine from your body. Your doctor may ask you to do a creatinine clearance test to see how well your kidneys are working.
It’s important to collect all of your urine for the whole 24-hour collection period. If you don’t collect all of your urine, our lab may not be able to complete your total protein evaluation.
Instructions for your urine collection
Your nurse will give you the following supplies:
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A plastic container to collect your urine.
- If you’re male, they’ll give you a handheld urinal.
- If you’re female, they’ll give you a urine collection “hat.”
- If you’re staying in the hospital, they may give you a bedpan.
- A plastic container to store your urine. Write your name on the label.
Right before your 24-hour urine collection period
You must start your urine collection period with an empty bladder. Right before you start the 24-hour collection period, urinate into the toilet and flush it. Then, write down the time and date. This is the start time of your urine collection period. It will end 24 hours later.
During your 24-hour urine collection period
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Collect all of your urine. Only urinate into the urinal, collection hat, or bedpan.
- To use the urine collection hat, place it under the toilet seat and urinate into it.
- If you’re staying in the hospital, ask for help if you need it.
- Don’t put toilet paper in the urinal, collection hat, or bedpan. Put it in the toilet and flush it.
- Each time you urinate, pour the urine from the urinal or collection hat into the labeled container. If you’re using a bedpan, ask your nurse or nursing assistant to do this for you.
- Make sure to drink at least 8 (8-ounce) glasses of liquids during your 24-hour collection period. If you’re staying in the hospital, you may also get fluids intravenously (through a vein).
Store the labeled container in the refrigerator. The urine must be kept cool at all times. If you do not have space in the refrigerator, you can store it in a cooler on top of ice. Add more ice as needed to keep the urine cold.
After your 24-hour urine collection period
If you collected your urine while you were at home:
- You’ll have an appointment within 24 hours after your urine collection period ends. Bring your labeled urine container to your appointment.
- Tell your nurse if you forgot to save any of your urine during the collection period.
- You’ll have blood drawn for a creatinine blood test when you return your urine collection container.
If you collected your urine while you were in the hospital:
- A nurse or nursing assistant will collect your labeled urine container.
- Tell your nurse or nursing assistant if you forgot to save any of your urine during the collection period.
- You’ll have blood drawn for a creatinine blood test the day your urine collection period ends.
