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Serum Creatinine Concentration (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
5401-5
Short code
VZV Ab Titr Ser CF
Synonyms
VZV Ab Titr Ser CF
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
comp-fix
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 metabolism that your kidneys normally filter out of your blood. High levels can suggest kidney problems, while low levels may indicate dehydration or other conditions. This test is often used alongside other kidney function tests to monitor overall kidney health.

Why Is This Test Done?

Doctors may order this test to evaluate kidney function, diagnose kidney disease, or monitor chronic conditions like diabetes or heart disease. It can also help determine if you need dialysis or other kidney treatments.

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

What Do Results Mean?

Results are compared to a reference range specific to your age, sex, and health status. Elevated levels may signal impaired kidney function, while persistently low levels could raise concerns about hydration or other metabolic issues.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Creatinine

Frequently asked questions

How often should I get this test?
Your doctor will determine how often you need this test based on your health condition. Regular monitoring is common for people with kidney disease, diabetes, or heart problems.
Can diet affect my creatinine levels?
Dietary protein intake can influence creatinine levels, as muscle breakdown produces this waste product. High-protein diets may temporarily raise levels, but this is usually short-term and not clinically significant unless you have kidney issues.
What if my results are outside the normal range?
If your results are abnormal, your doctor will discuss next steps, which may include further testing, lifestyle changes, or treatment adjustments. Follow-up visits are often needed to track kidney function over time.
  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