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Serum Creatinine (Creatinine Level)

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 via creatinine levels.

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

Key facts at a glance

LOINC
64314-8
Short code
FULLTIMESOCIALWORKERSTAFFPOSITIONSVACANTATENDOFPERIOD
Synonyms
—
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?

Your doctor may order this test to evaluate kidney health, monitor kidney disease progression, or check for conditions like dehydration, heart failure, or muscle disorders. It’s often used alongside other tests to diagnose or monitor chronic kidney disease.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm to draw blood. If you’re on a low-protein diet or have recent muscle injury, your doctor may advise adjustments.

What the Results Mean

Higher than expected levels may indicate poor kidney function, while lower levels could suggest overhydration or muscle breakdown. Results are interpreted in relation to your overall health and other tests.

Common Conditions Monitored

This test is critical for diagnosing or managing chronic kidney disease, kidney stones, dehydration, heart conditions, and muscle disorders like myopathy.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Elevated creatinine levels often signal impaired kidney function, as creatinine is a byproduct filtered by the kidneys. Low levels may reflect conditions like overhydration or muscle wasting, but interpretation depends on clinical context and other factors.

Short name

None

Frequently asked questions

What causes creatinine levels to be higher than normal?
Higher-than-normal creatinine levels can result from reduced kidney function, dehydration, muscle diseases, or conditions that increase muscle breakdown (e.g., severe illness or trauma).
How often should I get this test?
Frequency depends on your health status. People with kidney disease may need tests every few months, while others with stable conditions may only need occasional checks.
Can diet affect creatinine levels?
Dietary protein intake can influence creatinine levels, but the test itself measures waste from muscle metabolism, not protein directly. High protein intake may temporarily raise levels, but your doctor will consider this in 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