Skip to content

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 check via blood waste product levels.

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

Key facts at a glance

LOINC
28158-4
Short code
MAYCHOOSETOSELFDELIVERATTHEEND
Synonyms
—
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
reported-living-hiv
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 well your kidneys are working. High levels may suggest kidney damage or disease, while low levels could indicate dehydration or other conditions affecting kidney function.

What to Expect Before the Test

No special preparation is needed unless your doctor instructs otherwise. You may have a small needle inserted into your arm or hand for a blood draw, which usually takes a few minutes.

Common Causes of Abnormal Results

Elevated creatinine levels may be due to kidney problems, dehydration, severe muscle breakdown, or conditions like heart failure. Low levels might be linked to dehydration, overhydration, or certain medications.

How Results Are Used

Doctors use creatinine levels to monitor kidney function, diagnose kidney disease, and guide treatment plans for conditions like diabetes or high blood pressure.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Kidney Function and Health

Short name

Creatinine

Frequently asked questions

What does a creatinine test tell me about my health?
A creatinine test helps assess kidney function by measuring waste products in your blood. It’s often used alongside other tests to detect early kidney issues, track kidney disease progression, or evaluate responses to treatments.
Can diet or exercise affect my creatinine levels?
Diet high in protein or muscle activity can temporarily raise creatinine levels. Staying hydrated and following your doctor’s advice for diet and activity can help maintain stable results.
What if my results are outside the normal range?
If your results are abnormal, your doctor will discuss potential causes and next steps, such as further testing or lifestyle changes. Always follow their guidance.
  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