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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 serum. It helps assess how well your kidneys are filtering blood.

Quick summary

["Kidney function depends on this test to detect early kidney problems."]

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

Key facts at a glance

LOINC
50738-4
Short code
SRA LMW Pnl Ser
Synonyms
SRA LMW Pnl Ser
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 This Test Matters

Creatinine levels can indicate how efficiently your kidneys remove waste. High levels may suggest kidney damage or disease, while low levels could signal dehydration or muscle disorders.

What to Expect Before the Test

No special preparation is needed, but avoid heavy exercise or high-protein meals 24 hours before testing. Drink water as usual unless instructed otherwise.

Common Causes of Abnormal Results

Elevated creatinine may result from kidney disease, dehydration, or severe muscle breakdown. Low levels might occur with dehydration, low muscle mass, or certain liver/kidney disorders.

How Results Are Interpreted

Results are compared to your baseline or general reference ranges. Your doctor will consider your overall health, symptoms, and other tests to interpret results accurately.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Serum Creatinine

Frequently asked questions

How often should I get this test?
Your doctor will determine how often you need this test based on your health status. For example, people with diabetes, high blood pressure, or a history of kidney issues may need more frequent checks.
What does a ‘normal’ range mean?
A ‘normal’ range means your creatinine level falls within typical values for healthy adults, but this can vary slightly by lab and individual factors. Your doctor will discuss what your specific result means for you.
Can diet affect this test?
Yes, high-protein diets or muscle-building exercises can temporarily raise creatinine levels. Avoid extreme changes to your diet before testing unless advised by your healthcare provider.
  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