Skip to content

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 breakdown, in your blood or plasma. 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
35216-1
Short code
UIBC SerPl-msCnc
Synonyms
UIBC SerPl-msCnc
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 Is This Test Done?

Your doctor may order this test to monitor kidney health, especially if you have symptoms like fatigue, swelling, or changes in urine output. It’s also used before surgeries, during pregnancy, or if you have conditions like diabetes or high blood pressure that can affect kidneys.

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 larger panel. Bring any medications you’re taking to your appointment.

What Happens During the Test?

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

What Do the Results Mean?

Higher than expected levels may indicate poor kidney function, while lower levels could suggest dehydration or muscle breakdown. Your doctor will interpret results in relation to your overall health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Creatinine levels are a key marker for kidney function because it reflects how well blood is filtered. Elevated levels often signal kidney damage, chronic kidney disease, or conditions like glomerulonephritis. It’s also used alongside other tests (like blood urea nitrogen) to diagnose and monitor kidney-related issues.

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 more frequently, while others with stable health may only need it occasionally.
What can affect my creatinine levels?
Several factors can influence creatinine levels, including muscle mass (higher muscle = higher creatinine), dehydration, certain medications, or conditions like heart failure or liver disease. Always discuss any changes in your health or medications with your provider.
Is there anything I can do to prepare for this test?
Avoid strenuous exercise or heavy meals 24 hours before the test, as they may temporarily alter results. Stay hydrated unless your doctor advises otherwise, as dehydration can raise creatinine levels.
  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