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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 check: creatinine levels help determine if your kidneys are working properly."]

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

Key facts at a glance

LOINC
24710-6
Short code
MR Forearm
Synonyms
MR Forearm
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
mr
CPT
86430
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

What Does This Test Measure?

Creatinine is a byproduct of muscle breakdown that your kidneys filter from your blood. High levels may indicate reduced kidney function, while low levels could suggest muscle weakness or dehydration.

Why Might You Need This Test?

Doctors order creatinine tests to monitor kidney health, especially in people with diabetes, high blood pressure, or a history of kidney disease. It’s also used before certain medications or procedures to check kidney function.

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 levels. No special preparation is needed, but fasting may be advised in some cases.

What Are Common Results?

Results are compared to a general reference range, though individual ranges can vary by lab. High levels may signal kidney problems, while very low levels might need further investigation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine

Frequently asked questions

Why do I need this test?
Your doctor may recommend this test if you have symptoms like fatigue, swelling, or changes in urine, or if you’re at risk for kidney issues (e.g., diabetes, heart disease). It’s also part of routine check-ups for some conditions.
What do my results mean?
If your results are outside the normal range, your doctor will discuss next steps, such as further kidney tests or adjustments to your treatment plan. Results alone don’t diagnose a condition—your doctor will interpret them with your full medical picture.
Can I eat or drink before the test?
Most labs don’t require fasting for a basic creatinine test, but always follow your doctor’s instructions. If you’re unsure, ask before your appointment.
  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