Skip to content

Serum Creatinine Concentration (Mass)

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

["Your kidneys filter waste like creatinine; high levels may signal kidney problems."]

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

Key facts at a glance

LOINC
9469-8
Short code
Cr Wat-mCnc
Synonyms
Cr Wat-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 Is Done

Doctors may order this test to check how well your kidneys are working, especially if you have symptoms like fatigue, swelling, or changes in urine output. It’s also used before certain procedures or surgeries to evaluate kidney health.

What to Expect Before the Test

No special preparation is needed, but inform your doctor about any medications (especially pain relievers or diuretics) or recent illnesses, as they can affect results.

How the Test Works

A blood sample is taken from a vein in your arm. The lab measures the creatinine level using a method that detects its concentration in the serum.

Possible Results and Their Meaning

Higher-than-normal levels may indicate reduced kidney function, while lower levels could suggest dehydration or muscle breakdown. Results alone don’t diagnose kidney disease—your doctor will interpret them with other factors.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Serum Creatinine

Frequently asked questions

What might cause elevated creatinine levels?
Elevated creatinine can result from kidney disease, dehydration, severe muscle injury, or conditions that reduce blood flow to the kidneys. It’s not a standalone test but part of a broader evaluation.
Can creatinine levels change with diet?
Yes, high-protein foods or muscle activity can temporarily raise creatinine levels. Your doctor may adjust diet or timing of tests if needed.
Does this test detect kidney disease early?
No single test does, but creatinine is a key marker. Regular monitoring (e.g., with blood and urine tests) helps track kidney health 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