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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 and waste removal depend on this test."]

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

Key facts at a glance

LOINC
97642-3
Short code
dRVVT/dRVVT cfm Nrmlzd PPP-Rto
Synonyms
dRVVT/dRVVT cfm Nrmlzd PPP-Rto
Category
chemistry
Sample
plasma
Container
Lavender-top (EDTA) or Green-top (Heparin)
Units
N/A
Fasting
true
Population
adult
Sex
all
Age range
18–65 years
Method
coag
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 check for kidney problems, monitor kidney function over time, or evaluate conditions that affect how your kidneys work, such as diabetes or high blood pressure. It can also help determine if you need dialysis or other kidney treatments.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it’s part of a broader kidney function panel. Drink plenty of water the day before to help your kidneys produce urine for testing.

What Happens During the Test?

A healthcare provider will draw blood from a vein in your arm. The process is quick and typically causes only mild discomfort. The sample is sent to a lab for analysis.

What Do the Results Mean?

Higher-than-normal levels may indicate kidney problems, poor kidney function, or conditions that increase muscle breakdown (e.g., severe illness). Lower-than-normal levels could suggest dehydration or overuse of certain medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

This test is a key marker for kidney health. Elevated levels often signal reduced kidney function, which can lead to complications like fluid buildup, high blood pressure, or anemia. It’s also used to guide treatment decisions for chronic kidney disease.

Short name

Creatinine

Frequently asked questions

What causes creatinine levels to change?
Changes in creatinine levels can result from kidney disease, dehydration, muscle disorders, certain medications (like NSAIDs), or conditions that affect muscle metabolism. It’s important to discuss any recent changes in health or medications with your doctor.
How often should I get this test?
Your doctor will determine the frequency based on your health status. People with kidney disease may need tests more often, while others with stable conditions might have yearly checks. Follow your doctor’s recommendations.
Can diet or exercise affect creatinine levels?
Dietary protein intake and muscle mass can influence creatinine levels, but they don’t directly alter the test result itself. Staying hydrated and maintaining a balanced diet can help support overall kidney function, though it won’t change the test outcome directly.
  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