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Creatinine Clearance (from Serum)

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

This test measures how well your kidneys filter waste products like creatinine from your blood, helping assess kidney function.

Quick summary

["A measure of kidney function and blood flow efficiency."]

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

Key facts at a glance

LOINC
50757-4
Short code
CK/CK MB Bld-cRto
Synonyms
CK/CK MB Bld-cRto
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
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
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your doctor may order this test to evaluate kidney health, especially if you have symptoms like fatigue, swelling, or changes in urine output. It’s also used before surgeries, to monitor chronic kidney disease, or to check for dehydration or fluid overload.

How Is It Performed?

You’ll provide a blood sample (serum) and, depending on the protocol, may also have a timed urine collection. The test measures creatinine levels in blood and urine to calculate clearance.

What Does the Result Mean?

Lower than expected values might indicate overhydration or errors in urine collection. Higher values could suggest kidney dysfunction, dehydration, or muscle breakdown. Results are interpreted in context with your overall health.

Common Causes of Abnormal Results

Abnormal results may stem from kidney disease, heart failure, severe dehydration, or conditions affecting muscle mass. Your doctor will review your medical history and other test results to determine the cause.

Reference range

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

Specimen: whole-blood

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

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Creatinine Clearance

Frequently asked questions

How often will I need this test?
Frequency depends on your health status. Healthy adults may not need it unless monitored for kidney-related conditions. Those with chronic kidney disease or risk factors may need it more often.
Can I eat or drink before this test?
Typically, fasting is not required, but follow your lab’s instructions. Avoid excessive caffeine or alcohol before testing, as they may affect results.
What if my results are out of range?
Your doctor will discuss findings with you. They may recommend further tests or adjustments to your treatment plan based on the results.
  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