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Serum Creatinine (Creatinine)

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

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

Quick summary

["Your kidneys filter waste from blood; this test checks kidney function."]

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

Key facts at a glance

LOINC
110748-1
Short code
SLEV IgG Msmt Ser
Synonyms
SLEV IgG Msmt Ser
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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, especially if you have symptoms like fatigue, swelling, or changes in urine output. It’s also used before certain procedures or medications to ensure kidney safety.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the test if it’s part of a larger panel. Bring any medications or questions to your doctor.

What Happens During the Test?

A healthcare provider will draw blood from a vein in your arm. The process is quick and usually painless, with minimal discomfort afterward.

What the Results Mean

Higher-than-normal levels may suggest kidney problems, while lower levels could indicate dehydration or muscle breakdown. Your doctor will interpret results in relation to your health history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Creatinine levels are a key marker for kidney function. Elevated levels often indicate reduced kidney filtration, which can signal early kidney disease. It’s also used to assess kidney damage from conditions like diabetes or high blood pressure.

Short name

Creatinine

Frequently asked questions

What causes creatinine levels to change?
Creatinine levels can rise due to kidney disease, dehydration, or muscle disorders (e.g., severe muscle injury). They may drop if you’re overhydrated or have low muscle mass.
How often should I get this test?
Your doctor will determine frequency based on your health needs. Regular monitoring may be recommended if you have kidney-related conditions or risk factors like diabetes or hypertension.
Can diet affect creatinine levels?
Dietary protein intake can influence creatinine levels, but the impact is usually small. Avoiding excessive protein may help if your doctor advises it for kidney health.
  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