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Serum or Plasma Creatinine Concentration (Standard Method)

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

This test measures the amount of creatinine, a waste product from muscle breakdown, in your blood. It helps assess how well your kidneys are filtering blood.

Quick summary

["A creatinine test helps check kidney function by measuring waste in your blood."]

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

Key facts at a glance

LOINC
94436-3
Short code
HLA-DQB1 IgG SerPl FC
Synonyms
HLA-DQB1 IgG SerPl FC
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
flow-cytometry
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

Why This Test Matters

Your kidneys normally filter waste products, including creatinine, from your blood. High levels may indicate poor kidney function or damage, while low levels could suggest dehydration or muscle loss. This test is often used alongside other kidney function tests to monitor conditions like chronic kidney disease, kidney stones, or kidney failure.

What to Expect Before the Test

No special preparation is needed, but you may be asked to avoid certain medications or supplements that could affect results. If you have a recent meal, drink plenty of water before your blood draw to ensure accurate results.

How the Test Is Performed

A healthcare provider will draw blood from a vein in your arm using a small needle. You may feel a slight pinch, but the procedure is quick and usually painless. The blood sample is then sent to a lab for analysis.

What the Results Mean

Results are typically reported in milligrams per deciliter (mg/dL) or other units depending on the lab. While reference ranges vary by lab, higher than expected levels may signal kidney issues, while very low levels may need further investigation.

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 may recommend this test periodically if you have kidney problems, high blood pressure, diabetes, or a family history of kidney disease. Others may get it as part of routine health checks or if experiencing symptoms like fatigue, swelling, or frequent urination.
What causes creatinine levels to change?
Creatinine levels can rise due to kidney disease, dehydration, or muscle disorders. They may drop if you’re severely dehydrated or have lost muscle mass. Certain medications or conditions like heart failure can also affect results.
Do I need to fast before this test?
No fasting is required for this test, but drinking water beforehand can help ensure accurate results. If you’re unsure, always follow your healthcare provider’s instructions.
  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