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Creatinine Clearance (Serum-Based)

Published: August 9, 2026Updated: August 17, 2026

This test measures how well your kidneys filter waste products from your blood, using your serum creatinine levels and urine flow. It helps assess kidney function and glomerular filtration rate.

Quick summary

["A simple way to check how well your kidneys are working by linking blood and urine measurements."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
2157-6
Short code
CK SerPl-cCnc
Synonyms
CK SerPl-cCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
22
Ref high
198
Critical range
— – 10000 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82553
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 Matters

Creatinine clearance is a critical measure for diagnosing and monitoring kidney disease. It reflects how efficiently your kidneys remove waste products, like creatinine, from your blood. Unlike serum creatinine alone, this test accounts for urine output, giving a more accurate picture of kidney function over time.

How It’s Done

Your doctor will likely order a 24-hour urine collection to measure creatinine clearance. You’ll collect all urine for a full day, then provide a serum blood sample. Alternatively, some labs may use a simplified method with a single urine sample and blood draw, but the 24-hour method is more precise.

What to Expect Before the Test

No special preparation is needed for a 24-hour urine test, but you may be asked to avoid certain medications that could affect urine output. For blood tests, fasting isn’t required, but let your doctor know about any medications you’re taking, as they may influence results.

Common Reasons for Testing

Doctors order creatinine clearance when evaluating kidney disease, monitoring chronic conditions like diabetes or hypertension, or checking for signs of kidney damage before surgery. It’s also used to assess how well dialysis is working in patients on kidney replacement therapy.

Reference range

Adult males: 22-198 U/L; Females: 22-198 U/LN/A

Specimen: serum

No special preparation required. Inform provider of any chest pain or symptoms.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine Clearance

Frequently asked questions

What does a low creatinine clearance mean?
A low creatinine clearance suggests your kidneys aren’t filtering waste as well as they should, which may indicate early kidney disease or damage. This doesn’t always mean kidney failure, but it’s a sign your doctor should investigate further, possibly with additional tests.
Does diet affect creatinine clearance results?
Dietary protein intake can influence creatinine levels, but creatinine clearance itself is primarily based on urine volume and kidney function. High-protein diets may slightly raise creatinine in the blood, but the clearance test accounts for urine output, so diet changes alone won’t affect the final result unless they drastically alter urine production.
How often should I get this test?
Your doctor will determine how often you need this test based on your health condition. For people with kidney disease, diabetes, or hypertension, it may be checked every 3–6 months. If you’re healthy, it’s usually only ordered if you have symptoms or risk factors for kidney problems.
  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 17, 2026. · Read our editorial policy