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Serum or Plasma 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 or plasma. It helps assess how well your kidneys are filtering blood.

Quick summary

["A creatinine test helps check kidney function by measuring how well your kidneys remove waste from your blood."]

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

Key facts at a glance

LOINC
22414-7
Short code
MuV Ab Titr Ser
Synonyms
MuV Ab Titr Ser
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 Matters

Creatinine is a byproduct of muscle breakdown and is normally filtered out of your blood by your kidneys. If your kidneys aren’t working well, creatinine builds up in your blood. This test helps doctors determine if your kidneys are functioning properly or if there may be a problem.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast before the test, but this depends on the lab’s protocol. Bring any medications you’re currently taking, as some may affect 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. The blood sample is sent to a lab for analysis.

What the Results Mean

Results are compared to a reference range, which can vary slightly by lab. High levels may indicate kidney problems, while low levels could suggest muscle breakdown or other conditions. Your doctor will interpret the 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

What could cause abnormal results?
High creatinine levels may signal kidney disease, dehydration, or conditions that reduce blood flow to the kidneys. Low levels might indicate muscle disorders, liver disease, or overhydration. Always discuss results with your doctor, as they’ll consider your full medical history.
How often should I get this test?
Your doctor may order this test regularly if you have kidney-related conditions, diabetes, high blood pressure, or other health issues that affect kidney function. Follow their guidance on testing frequency.
Does diet affect this test?
Yes, high-protein foods or muscle damage (like from intense exercise) can temporarily raise creatinine levels. Avoid excessive protein intake 24–48 hours before testing if advised by your doctor.
  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