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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 simple blood test."]

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

Key facts at a glance

LOINC
63341-2
Short code
ENA SS-A 52kD Ab CSF Ql IA
Synonyms
ENA SS-A 52kD Ab CSF Ql IA
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your doctor may order this test to check for kidney problems, monitor kidney disease, evaluate dehydration, or assess overall kidney function. It’s also used before certain procedures or surgeries to ensure your kidneys are working properly.

What Does a High or Low Level Mean?

High levels may indicate kidney disease, dehydration, or conditions that reduce blood flow to the kidneys. Low levels could suggest overhydration, liver disease, or muscle disorders that affect creatinine production.

How Is the Test Performed?

A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where it’s analyzed to measure creatinine concentration.

What Should You Do Before the Test?

Avoid strenuous exercise or heavy meals 24 hours before the test. If you’re on certain medications (like NSAIDs), ask your doctor if you should stop them temporarily.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine

Frequently asked questions

Creatinine levels are a key marker for kidney function. While they don’t diagnose kidney disease directly, they help doctors track how well your kidneys are filtering blood over time. Chronic kidney disease may show up as steadily rising levels, while acute kidney problems may cause sudden spikes.
This test alone doesn’t confirm kidney disease—it’s often used alongside other tests (like urine tests or blood pressure checks) for a full picture. If your levels are abnormal, your doctor may recommend further evaluation.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Your doctor will discuss the results with you during your follow-up visit.
Can diet or exercise affect creatinine levels?
Dietary protein intake can influence creatinine levels, but moderate changes are unlikely to cause noticeable fluctuations. High-intensity exercise may temporarily raise levels due to muscle breakdown, but it usually returns to normal afterward.
  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