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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 evaluate kidney function and detect early kidney problems."]

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

Key facts at a glance

LOINC
73560-5
Short code
MuV IgG+IgM Ser-Imp
Synonyms
MuV IgG+IgM Ser-Imp
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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 symptoms like swelling, fatigue, or changes in urine output. It’s often used alongside other tests to assess overall kidney health.

What Does the Result Mean?

Higher than expected levels may indicate poor kidney function, while lower levels could suggest overhydration or muscle breakdown. However, results alone don’t diagnose kidney issues—your doctor will consider other factors.

How Is This Test Performed?

A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where it’s analyzed to measure creatinine concentration using a specialized method.

What Should You Do Before the Test?

Avoid heavy exercise or extreme dehydration 24 hours before testing. If you’re on certain medications (like contrast dyes for imaging), ask your doctor first—these can affect results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Kidney Function and Disease Detection

Short name

Creatinine Level

Frequently asked questions

Creatinine levels are a key marker for kidney function because they reflect how well blood is filtered. Chronic kidney disease (CKD) often shows up early with subtle changes in creatinine, so regular monitoring is important for early intervention.
Your doctor may compare this result with previous tests or other kidney markers (like blood urea nitrogen) to assess trends and overall kidney health.
Can diet or medications affect this test?
Eating high-protein foods or taking certain supplements (like vitamin B6) shortly before testing may slightly alter creatinine levels. Always follow your doctor’s instructions for pre-test preparation.
How often should I get this test?
Frequency depends on your health status. People with diabetes, high blood pressure, or a family history of kidney disease may need it more often (e.g., every 6–12 months). Ask your doctor for personalized 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