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Creatinine Clearance (Calculated from Serum Creatinine and Estimated Glomerular Filtration Rate)

Published: August 9, 2026Updated: August 16, 2026

This test measures how well your kidneys filter waste products from your blood, using a simple calculation based on your blood and urine results.

Quick summary

["Helps assess kidney function and detect early kidney damage."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
104937-8
Short code
CT Spine mCnc for BMD
Synonyms
CT Spine mCnc for BMD
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

Why This Test Is Done

Doctors may order creatinine clearance to monitor kidney health, especially if you have conditions like high blood pressure, diabetes, or a family history of kidney disease. It’s also used before surgeries or treatments that could affect kidney function.

How the Test Works

Your blood is drawn to measure creatinine levels, and urine is collected over 24 hours (or estimated) to measure creatinine excretion. The test calculates how much creatinine your kidneys filter from your blood each minute.

Sample Collection

Blood: A simple fingerstick or vein draw provides serum (blood plasma after clotting). Urine: A 24-hour urine collection is standard, but some labs may estimate results using a single blood creatinine measurement and a formula.

What to Expect

Blood draw is quick and usually painless, while urine collection requires careful timing to ensure accuracy. Follow your doctor’s instructions to avoid foods like red meat or caffeine, which can temporarily affect creatinine levels.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Low creatinine clearance may indicate kidney disease, while very high levels could suggest dehydration or kidney damage. It’s a key tool for diagnosing and managing chronic kidney conditions, guiding treatments like dialysis or medication adjustments.

Short name

None

Frequently asked questions

How long does it take to get results?
Results are typically ready within 1–3 business days, depending on lab processing times.
What does a low or high creatinine clearance mean?
A low value may signal kidney problems, while a very high value could indicate dehydration or other health issues. Your doctor will interpret results in the context of your overall health.
Can diet affect this test?
Yes, foods like red meat, processed meats, and caffeine can temporarily raise creatinine levels. Follow your doctor’s advice on dietary restrictions before testing.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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