Urinary Creatinine-to-Creatinine Clearance Ratio (24-hour urine collection)
This test measures how well your kidneys filter waste products by comparing creatinine levels in your urine over 24 hours. It helps assess kidney function and blood flow to the kidneys.
["This test helps doctors evaluate kidney health and blood flow by tracking waste removal over a full day."]
Key facts at a glance
- LOINC
- 99901-1
- Short code
- Tri-Phos Cry #/area UrnS Comp Assist
- Synonyms
- Tri-Phos Cry #/area UrnS Comp Assist
- Category
- electrolyte
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- computer-assisted
- 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, poor kidney function, or conditions affecting blood flow to the kidneys. It can also be used to monitor chronic kidney conditions or after treatments that might impact kidney function.
How the Test Works
You’ll collect all urine for 24 hours in a special container. The test measures creatinine, a waste product naturally present in your blood and urine, to estimate how well your kidneys filter it out.
Sample Collection
You’ll start collecting urine immediately after waking up, emptying your bladder into the container, and continue until you collect urine for the next 24 hours. Discard the first morning urine to avoid contamination. Store the urine in a cool place and return it to your doctor’s office or lab on time.
What to Expect
No special preparation is needed, but avoid strenuous activity or certain medications that could affect kidney function before testing. Follow your doctor’s instructions carefully.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Low results may indicate kidney disease, poor blood flow, or dehydration. High results could suggest kidney damage, obstruction, or conditions like polycystic kidney disease. This test helps diagnose and monitor kidney function and related conditions.
Short name
24-Hour Urine Creatinine Clearance
Frequently asked questions
What causes false low results?
What causes false high results?
How often should I get 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 16, 2026. · Read our editorial policy