Creatinine Clearance (from Serum Creatinine and Estimated Glomerular Filtration Rate)
This test measures how well your kidneys filter waste products from your blood, using a simple blood test and your urine output over time.
["Assesses kidney function by estimating how efficiently your kidneys remove waste from your blood."]
Key facts at a glance
- LOINC
- 35962-0
- Short code
- CT Elbow
- Synonyms
- CT Elbow
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ct
- 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
How the Test Works
Your blood sample is tested for creatinine levels, a waste product naturally produced by your muscles. Along with your urine volume over a set period (often 24 hours), this helps calculate how well your kidneys are filtering blood.
Why It Matters
Creatinine clearance helps doctors check if your kidneys are working properly, especially if you have symptoms like swelling, fatigue, or changes in urine output. It’s useful for monitoring kidney disease, managing medications, or planning treatments.
What to Expect Before the Test
No special preparation is needed for this test. If you’re having a 24-hour urine collection, you’ll need to collect all urine for a full day, including overnight. Drink plenty of water to support kidney function but avoid excessive diuretics unless advised by your doctor.
What to Expect During the Test
A blood sample is drawn from a vein in your arm, similar to other blood tests. If urine collection is involved, you’ll follow instructions to collect urine in a container over a specific time period. The test is quick and painless, though you may feel slight discomfort from the needle.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Creatinine Clearance
Frequently asked questions
A low creatinine clearance may indicate kidney damage or disease, while a very high clearance could suggest overhydration or other conditions. It’s often used alongside other tests to diagnose kidney problems, track progression of kidney disease, or guide treatment decisions for conditions like diabetes or high blood pressure.
If you have kidney disease, your doctor may recommend this test regularly to monitor your kidney function and adjust treatments as needed. It’s important to stay hydrated but avoid excessive fluids unless advised otherwise.
How long will I need to collect urine for 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