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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 breakdown, in your blood. It helps assess how well your kidneys are filtering blood.

Quick summary

["Your kidneys filter waste from your blood; high creatinine may signal kidney problems."]

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

Key facts at a glance

LOINC
44706-0
Short code
SMA IgG Ser-aCnc
Synonyms
SMA IgG Ser-aCnc
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 This Test Matters

Creatinine levels help doctors check kidney function. Kidneys normally remove waste like creatinine from your blood. If levels are too high, it may mean your kidneys aren’t working as well as they should, which can affect your overall health.

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 blood draw. Wear loose clothing for easy access to your arm.

How the Test Works

A healthcare provider will draw blood from a vein in your arm. The blood sample is sent to a lab where it’s tested for creatinine levels using a method that detects waste products in your blood.

What the Results Mean

Results are typically reported in milligrams per deciliter (mg/dL). Higher than expected levels may indicate kidney problems, while lower levels could suggest dehydration or muscle breakdown. Your doctor will interpret results in relation to your 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?
Several factors can raise creatinine levels, including kidney disease, dehydration, muscle disorders, or certain medications. If you’ve had recent muscle activity (like intense exercise), it may temporarily increase levels.
How often should I get this test?
Your doctor will determine how often you need this test based on your health history, symptoms, and kidney function. Some people get it yearly, while others may need it more often if they have chronic conditions like diabetes or high blood pressure.
Can diet or exercise affect creatinine levels?
Yes! High-protein diets or intense exercise can temporarily raise creatinine levels. Staying hydrated and maintaining a balanced diet can help keep levels stable. Always discuss dietary changes with your doctor.
  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