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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. It helps assess how well your kidneys are filtering blood.

Quick summary

["A creatinine test helps check kidney function and detect early kidney problems."]

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

Key facts at a glance

LOINC
23274-4
Short code
M gallisep Ab Titr Ser HA
Synonyms
M gallisep Ab Titr Ser HA
Category
coagulation
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ha
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 monitor kidney health, especially in people with diabetes, high blood pressure, or other conditions that can affect the kidneys.

How the Test Works

A small blood sample is taken from your arm and sent to a lab. The lab uses a specialized method (often an enzymatic or chemiluminescent assay) to measure the creatinine concentration in your blood plasma or serum.

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’s part of a broader kidney function panel. Let your healthcare provider know if you’re taking certain medications, as they could affect results.

What the Results Mean

Higher-than-normal creatinine levels may indicate reduced kidney function, while lower levels could suggest overhydration or muscle loss. Your doctor will compare your results with your baseline and other tests to interpret them accurately.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Creatinine Level

Frequently asked questions

What could cause elevated creatinine levels?
Elevated creatinine levels can be caused by kidney disease, dehydration, severe muscle damage, or certain medications. Low levels may occur with overhydration, liver disease, or conditions that reduce muscle mass.
How often should I get this test?
Your doctor will determine how often you need this test based on your health history, symptoms, and other tests. Regular monitoring may be recommended if you have kidney-related conditions or risk factors.
Can diet affect creatinine levels?
Dietary changes alone won’t significantly alter creatinine levels, but eating a high-protein diet in large amounts over time *might* temporarily increase muscle breakdown and indirectly affect results. Always follow your doctor’s guidance.
  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