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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 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
33095-1
Short code
GA from CRL.Shinozuka96
Synonyms
GA from CRL.Shinozuka96
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
us-estimated-from-crl-shinozuka
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 monitor kidney health because they reflect how efficiently your kidneys remove waste from your blood. High levels may indicate kidney damage or disease, while low levels could suggest dehydration or other conditions affecting fluid balance.

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 broader metabolic panel. Drink plenty of water the day before to ensure accurate results.

Common Causes of Abnormal Results

High creatinine levels may be caused by kidney disease, dehydration, severe muscle injury, or conditions that reduce blood flow to the kidneys. Low levels might result from overhydration, liver disease, or certain medications.

How Results Are Interpreted

Your doctor will compare your results to standard ranges and consider your overall health. They may also check other tests, like blood urea nitrogen (BUN), to get a clearer picture of kidney function.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Creatinine

Frequently asked questions

Will my creatinine level affect my treatment?
Yes, if your levels are abnormal, your doctor may adjust medications, recommend lifestyle changes (like hydration or diet), or monitor kidney function more closely. Always follow their guidance.
Can diet or exercise change my creatinine level?
Dietary protein intake and muscle mass can influence creatinine levels. High-protein foods or intense exercise may temporarily raise them, but this usually isn’t a cause for concern unless your doctor notes it.
What if my test shows a borderline result?
Borderline results often need follow-up testing to confirm trends. Your doctor may repeat the test or order additional tests to investigate further, especially if you have symptoms like fatigue or swelling.
  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