Creatinine Clearance (Serum-Based, 24-Hour Urine Collection)
This test measures how well your kidneys filter waste products from your blood, using a 24-hour urine sample and your serum creatinine level. It helps assess kidney function and blood flow.
["A creatinine clearance test helps doctors check if your kidneys are working properly and identify potential kidney problems early."]
Key facts at a glance
- LOINC
- 44993-4
- Short code
- C trach C IgA Ser Ql
- Synonyms
- C trach C IgA Ser Ql
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82784
- 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
What Is Creatinine Clearance?
Creatinine clearance is a measure of how efficiently your kidneys remove creatinine, a waste product from muscle metabolism, from your blood. Unlike a single serum creatinine test, this test accounts for both your blood creatinine level and the total urine creatinine excreted over 24 hours, giving a more accurate picture of kidney function.
Why Is This Test Done?
Your doctor may order this test if you have symptoms like fatigue, swelling, or frequent urination, or if they suspect kidney disease. It’s also used before surgeries, during pregnancy, or to monitor chronic conditions like diabetes or high blood pressure.
How Is the Test Performed?
You’ll collect all urine for 24 hours in a special container, starting after your first morning urine. Your blood is drawn once to measure serum creatinine. The test requires careful timing to ensure accurate results.
What Are the Results?
Results are typically reported as a clearance rate (e.g., mL/min or mL/hr), comparing your kidney function to healthy ranges. Lower values may indicate reduced kidney function.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A creatinine clearance test is critical for diagnosing and managing kidney disease. Abnormal results can signal early kidney damage, guide treatment plans, or help prevent complications from conditions like diabetes or hypertension.
Short name
Creatinine Clearance
Frequently asked questions
How long does the 24-hour urine collection take?
What if I miss any urine during the collection?
Can I take my usual medications during urine collection?
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