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Creatinine (from whole blood) measured by mass concentration via enzymatic method

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

This test measures the amount of creatinine, a waste product from muscle metabolism, in your blood. It helps assess how well your kidneys are filtering blood.

Quick summary

["Kidney function check with a simple blood test."]

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

Key facts at a glance

LOINC
23749-5
Short code
Lead Spec-mCnc
Synonyms
Lead Spec-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 Is This Test Done?

Doctors may order this test to evaluate kidney function, monitor chronic kidney disease, check for kidney-related conditions, or assess overall health before certain procedures. It’s also used to monitor treatments for conditions affecting kidney function.

What Does the Test Involve?

A small blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where it’s analyzed to measure creatinine levels.

What Are Common Results and What Do They Mean?

While specific reference ranges vary by lab, higher than expected levels may suggest impaired kidney function, while lower levels could indicate muscle underuse or other metabolic issues. Your results will be interpreted by your healthcare provider based on your overall health.

How Is This Test Different from Other Kidney Tests?

Unlike tests like blood urea nitrogen (BUN), which also assess kidney function, creatinine specifically measures the waste product from muscle breakdown. Together, these tests can provide a more complete picture of kidney health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine

Frequently asked questions

What causes creatinine levels to be higher than normal?
Higher-than-normal creatinine levels can result from kidney disease, dehydration, severe muscle damage, or certain medications. If you’ve had recent exercise, muscle injury, or a high-protein diet, these may temporarily affect results.
What if my creatinine level is low?
Low creatinine levels might suggest muscle underuse, malnutrition, or liver disease, which can reduce muscle mass or affect waste metabolism. Your doctor will consider other factors, like your age or activity level, when interpreting results.
Do I need to prepare for this test?
No special preparation is needed, but avoid strenuous exercise 24 hours before the test. If you’re on certain medications (like NSAIDs), let your doctor know, as they may affect kidney function and test 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 16, 2026. · Read our editorial policy