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Serum Creatinine (Mass Concentration)

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of creatinine, a waste product from muscle metabolism, in your blood serum. It helps assess kidney function.

Quick summary

["A key indicator of how well your kidneys filter blood."]

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

Key facts at a glance

LOINC
28546-0
Short code
N men sg A IgG Ser IA-mCnc
Synonyms
N men sg A IgG Ser IA-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
CPT
82784
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 Is Creatinine?

Creatinine is a byproduct of muscle breakdown that your kidneys normally filter out of your blood. High levels can suggest kidney problems, even if you don’t have symptoms yet.

Why Is This Test Done?

Your doctor may order this test to check kidney function, monitor chronic kidney disease, or evaluate conditions affecting blood flow to the kidneys.

How Is the Sample Collected?

A blood sample is taken from a vein, usually in your arm. You may feel a small pinch, but it’s quick and painless. No special preparation is needed.

What Does the Result Mean?

Results alone don’t diagnose kidney issues—they’re part of a bigger picture. Your doctor will compare your levels to your health history and other tests.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine

Frequently asked questions

How often should I get this test?
Your doctor will decide based on your medical needs. Some people get it yearly, while others need it more often if they have kidney-related conditions.
Can diet affect creatinine levels?
Dietary protein intake can influence creatinine levels, but the test itself doesn’t measure protein directly. Your doctor may ask about diet if needed for context.
What if my result is out of range?
If your result is unusual, your doctor will discuss it with you. They may recommend follow-up tests or changes to your treatment plan.
  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