24-Hour Urinary Creatinine Clearance
This test measures how well your kidneys filter waste products, specifically creatinine, over a full day using your urine.
["Assesses kidney function by tracking how efficiently your kidneys remove waste from your blood over 24 hours."]
Key facts at a glance
- LOINC
- 1369-8
- Short code
- Vit C p PO 24h Ur-mRate
- Synonyms
- Vit C p PO 24h Ur-mRate
- Category
- chemistry
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 80
- Ref high
- 100
- 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
Why This Test Is Done
Your doctor may order this test if they suspect kidney disease, evaluate kidney function after a medical event (like an injury or illness), or check how well medications are being processed by your kidneys. It helps determine if your kidneys are working as they should.
How the Test Works
You’ll collect all your urine for a full 24-hour period in a special container. The test measures creatinine levels in both your urine and blood to calculate how much creatinine your kidneys remove from your blood over time.
Sample Collection Process
You’ll start by emptying your bladder into the container at the beginning of the 24-hour period. After that, every time you urinate, you’ll pour the urine into the container. At the end of 24 hours, you’ll measure the total urine volume and send both the urine sample and a fresh blood sample to the lab.
What to Expect
You’ll need to keep a diary of all urine output to ensure accuracy. Avoid certain medications that could affect creatinine levels (like some pain relievers or contrast dyes) unless approved by your doctor. Drink plenty of fluids to support kidney function during this period.
Reference range
NCBI: PaO2 80-100 mmHgN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Creatinine Clearance (24h)
Frequently asked questions
This test is crucial for diagnosing and monitoring kidney disease, including conditions like chronic kidney disease or acute kidney injury. It helps assess how well your kidneys are filtering waste and can identify early signs of impaired kidney function that might not be detected by other tests alone.
How often is this test repeated? Your doctor may repeat this test if they need to monitor kidney function over time, especially if you have an ongoing health condition affecting your kidneys.
Is there any risk or discomfort with this test? The process involves collecting urine over 24 hours, which may require careful tracking, but there are no invasive procedures or risks associated with this 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 17, 2026. · Read our editorial policy