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Serum or Plasma Creatinine Concentration (Substance 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
53534-4
Short code
VZV IgG Fld Ql IA
Synonyms
VZV IgG Fld Ql IA
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
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 monitor kidney health, especially if you have symptoms like swelling, fatigue, or changes in urine output. It’s also used before surgeries, during pregnancy, or when managing conditions like diabetes or high blood pressure.

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. Wear comfortable clothing for blood draws.

How the Test Is Done

A healthcare provider will take a small blood sample from a vein, usually in your arm. The sample is sent to a lab for analysis.

What the Results Mean

Higher-than-normal levels may signal kidney issues, while lower levels could indicate 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.

◆Associated findings1

Short name

Creatinine

Frequently asked questions

What causes creatinine levels to change?
Creatinine levels can rise due to kidney problems, dehydration, or muscle disorders (e.g., severe muscle damage). They may also drop if you’re overhydrated or have a rare metabolic condition.
How often should I get this test?
Your doctor will determine how often you need this test based on your health needs. For example, people with kidney disease may need it monthly or more frequently.
Can diet affect creatinine levels?
Dietary changes like eating more protein or consuming large amounts of meat can temporarily raise creatinine levels, but this effect is usually short-term and depends on kidney function.
  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