Creatinine Clearance (24-hour urine collection)
This test measures how well your kidneys filter waste products from your blood over a 24-hour period by analyzing urine and blood samples.
["Assesses kidney function by evaluating urine flow and blood waste levels."]
Key facts at a glance
- LOINC
- 26815-1
- Short code
- Cocaethylene Mec-mCnt
- Synonyms
- Cocaethylene Mec-mCnt
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why It’s Done
Your doctor may order this test to check if your kidneys are working properly, especially if you have symptoms like fatigue, swelling, or changes in urine output. It helps diagnose or monitor conditions like chronic kidney disease, dehydration, or kidney-related medications.
How It Works
You’ll collect all urine for 24 hours (typically from one morning to the next) in a container. A blood sample is also taken. The test compares the amount of creatinine in your urine and blood to estimate how well your kidneys filter waste.
Sample Collection
For urine: Empty your bladder at the start of the 24-hour period, then collect every drop for the full 24 hours. For blood: A small sample is drawn from a vein, usually in your arm.
What to Expect
Urine collection may require a timed period at home. Blood draws are quick but may cause slight discomfort. Follow your doctor’s instructions carefully to ensure accurate results.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
None
Frequently asked questions
Low creatinine clearance may indicate poor kidney function, while high values could suggest dehydration or overhydration. It’s critical for managing kidney health, especially in patients with diabetes, high blood pressure, or other chronic conditions.
How long does it take to get results? Results are typically ready within a few days to a week, depending on your lab’s processing time.
What if I miss any urine during the 24-hour collection? If you miss even a small amount, your results may be inaccurate. Double-check your collection time and accuracy with your healthcare provider.
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