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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 breakdown, 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
32007-7
Short code
C trach G+F+K Ab Titr Ser
Synonyms
C trach G+F+K 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 metabolism that your kidneys filter out of your blood. High levels can indicate kidney damage or disease, while low levels may suggest dehydration or muscle loss. This test is often used alongside other kidney function tests to monitor overall kidney health.

What to Expect Before the Test

No special preparation is needed for this test. You may have a small needle inserted into your arm or vein to draw blood. If you’re concerned about pain, let your healthcare provider know. Avoid strenuous activity or excessive fluid intake 24 hours before the test if instructed.

Common Causes of Abnormal Results

High creatinine levels may be due to kidney disease, dehydration, severe muscle damage, or conditions like heart failure or diabetes. Low levels might result from dehydration, low muscle mass, or certain medications. Always discuss any symptoms or concerns with your doctor.

What the Results Mean

Your results will be compared to a reference range specific to your age, sex, and overall health. While exact values vary, consistently high or low levels may signal underlying issues that require further evaluation.

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 history, symptoms, and any conditions they’ve diagnosed. For example, people with diabetes or kidney disease may need it more frequently than others.
What can affect my creatinine levels?
Several factors can influence creatinine levels, including muscle mass (more muscle = higher levels), dehydration, recent exercise, or certain medications. If you’ve had recent surgery, trauma, or changes in diet, let your doctor know so they can interpret your results accurately.
Do I need to fast before this test?
No fasting is required for this test. Unlike some blood tests, you can eat and drink normally before having your blood drawn.
  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