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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 metabolism, in your blood. It helps assess how well your kidneys are filtering blood.

Quick summary

["Kidney function is often checked with creatinine levels to spot early kidney problems."]

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

Key facts at a glance

LOINC
24899-7
Short code
XR Ribs Views
Synonyms
XR Ribs Views
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
xr
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 Is This Test Done?

Your doctor may order this test to check for kidney disease, monitor kidney function over time, or evaluate how well medications are being processed by your kidneys. It can also help diagnose conditions like dehydration, heart failure, or certain metabolic disorders.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the test if it’s part of a broader metabolic panel. Avoid heavy exercise or strenuous activity the day before. If you’re on certain medications, let your doctor know.

What Happens During the Test?

A healthcare professional will draw blood from a vein in your arm. The sample is sent to a lab for analysis. The test typically takes a few minutes, and you may feel slight discomfort but no lasting effects.

What Are the Results Mean?

Results are compared to a general reference range, which can vary slightly by lab. High levels may suggest kidney issues, while low levels could indicate dehydration or muscle breakdown. Your doctor will interpret results in the context of your overall health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine Level

Frequently asked questions

How Often Should I Get This Test?
Your doctor will determine how often you need this test based on your health status. For example, people with kidney disease may need it monthly or more frequently, while others with stable conditions might get it once or twice a year.
Can I Eat or Drink Before the Test?
If fasting is required (as mentioned earlier), avoid food and liquids except water for the specified period. If no fasting is needed, you can eat and drink normally, but heavy meals may slightly affect results.
What If My Results Are Abnormal?
If your creatinine level is outside the expected range, your doctor will discuss it with you. They may recommend further tests, adjustments to your medications, or lifestyle changes to address any underlying issues.
  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