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Serum or plasma concentration of **creatinine** (mass concentration measurement)

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

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

Quick summary

["A creatinine test helps evaluate kidney function by checking how efficiently your kidneys remove waste from your blood."]

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

Key facts at a glance

LOINC
20983-3
Short code
WEEV Ab Ser Ql IF
Synonyms
WEEV Ab Ser Ql IF
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
if
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

Your healthcare provider may order this test if you have symptoms of kidney problems, such as swelling, fatigue, or changes in urine output. It may also be used to monitor kidney function in people with diabetes, high blood pressure, or other health conditions that can affect the kidneys.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the test if it involves a blood draw. If you’re taking certain medications, let your provider know, as they may affect results.

How the Test Is Performed

A healthcare professional will draw blood from a vein in your arm. The sample is then sent to a lab for analysis to measure creatinine levels.

What the Results Mean

Results are compared to a reference range, but exact values can vary by lab. High levels may indicate kidney disease, while very low levels could suggest muscle disorders or other conditions. Your provider will interpret results in the context of your overall health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Creatinine Level

Frequently asked questions

How does creatinine relate to kidney function?
Creatinine is a byproduct of muscle metabolism and is filtered by the kidneys. Elevated levels often signal impaired kidney function, helping doctors diagnose or monitor kidney disease early.
What if my creatinine level is outside the normal range?
If your results are abnormal, your provider may recommend further testing (like a kidney function panel) or adjustments to your treatment plan. Always discuss findings with them for personalized guidance.
Can diet or exercise affect creatinine levels?
Dietary protein intake and muscle mass influence creatinine levels, but the test itself doesn’t measure kidney function directly. Your provider will consider lifestyle factors when interpreting results.
  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