Creatinine, 24-Hour Urine
Measures the total creatinine excreted in urine collected for 24 hours to help assess kidney function and verify the completeness of urine collection.
["This test shows how much creatinine your kidneys excrete over a full day."]
Key facts at a glance
- LOINC
- 25847-5
- Short code
- AAA/Creat 24h Ur-sRto
- Synonyms
- AAA/Creat 24h Ur-sRto
- Category
- liver
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What is this test?
Creatinine is a waste product made by the muscles and filtered by the kidneys. This test measures the total amount of creatinine released in urine over 24 hours, rather than the concentration in a single urine sample.
Why might I need this test?
A 24-hour urine creatinine measurement can help assess kidney function and determine how much urine was actually collected. It may also be used when a healthcare professional is evaluating a person with suspected kidney disease.
How is the test performed?
All urine produced during a full 24-hour period is collected in a special container and sent to a laboratory for measurement. The start and end times are recorded so the laboratory can calculate the daily amount of creatinine.
How do I prepare for the test?
Follow the collection instructions provided by the laboratory, including the exact start and end times. Include every urine sample during the period, note any missed collections, and ask whether the container should be refrigerated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Creatinine excretion that is higher than expected may occur with increased muscle mass, intense exercise, pregnancy, or reduced kidney reabsorption. Lower excretion may reflect reduced kidney filtration, dehydration, very low muscle mass, or an incomplete collection. Results should be interpreted by a healthcare professional along with other kidney tests and clinical information.
Short name
24-Hour Urine Creatinine
Frequently asked questions
Do I need to fast for a 24-hour urine creatinine test?
What happens if I miss part of the urine collection?
Is this test the same as a creatinine blood test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy