Serum/plasma creatinine clearance (24-hour urine collection)
This test measures how well your kidneys filter waste from your blood over a 24-hour period, using both blood and urine samples.
Assesses kidney function by evaluating how efficiently waste is removed from your blood.
Key facts at a glance
- LOINC
- 64332-0
- Short code
- INCENTERPATIENTSTRANSFERREDFROMOTHERDIALYSISUNIT
- Synonyms
- —
- 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 This Test Is Done
Your healthcare provider may order this test if you have symptoms of kidney problems, such as fatigue, swelling, or changes in urine output. It’s also used to monitor kidney function in people with chronic conditions like diabetes or high blood pressure.
What to Expect Before the Test
You’ll need to collect all urine for a full 24-hour period (from one full wake-up to the next). Blood will be drawn at the start and end of this time. Follow your provider’s instructions carefully to ensure accurate results.
During the Test Process
Blood samples are taken at the start and end of your urine collection period. Your urine is collected in a container throughout the day. This test requires careful timing and consistency to measure waste removal accurately.
What the Results Mean
Results help determine if your kidneys are working as they should. Lower than expected values may indicate poor kidney function, while higher values could suggest overhydration or other conditions. Your provider will interpret results in relation to your overall health.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is critical for diagnosing and managing kidney disease. It helps track how well kidneys filter waste, guiding treatment decisions for conditions like chronic kidney disease, dialysis planning, or response to medications that affect kidney function.
Short name
None
Frequently asked questions
Why was I asked to collect urine for 24 hours?
If you miss any samples, your results may not be accurate. Follow your provider’s instructions precisely, including timing for blood draws and urine collection. Contact your provider immediately if you cannot complete the test as scheduled.
If you experience pain, bleeding, or unusual urine changes, notify your healthcare team right away. They may adjust your test plan or provide guidance to ensure accuracy.
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