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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 plasma. It helps assess how well your kidneys are filtering blood.

Quick summary

["A creatinine test helps check kidney function by tracking how well your kidneys remove waste from your blood."]

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

Key facts at a glance

LOINC
79172-3
Short code
GH 2.5h p chal SerPl-aCnc
Synonyms
GH 2.5h p chal SerPl-aCnc
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 Is Done

Your doctor may order this test if you have symptoms like swelling, fatigue, or changes in urine output. It’s also used to monitor kidney health in people with diabetes, high blood pressure, or other conditions that affect the kidneys.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 4–8 hours before the test if it’s part of a broader kidney function panel. Bring any medications you’re taking to your appointment.

How the Test Is Performed

A blood sample is drawn from a vein, usually in your arm. The blood is sent to a lab where it’s analyzed to measure creatinine levels.

What the Results Mean

Higher-than-normal creatinine levels may indicate reduced kidney function, while lower levels could suggest dehydration or overhydration. Your doctor will interpret results in relation to your overall health and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine Level

Frequently asked questions

What causes creatinine levels to change?
Creatinine levels can rise due to kidney disease, dehydration, or muscle disorders (e.g., severe muscle breakdown). They may also drop if you’re overhydrated or have conditions that reduce muscle mass.
How often should I get this test?
Your doctor will determine how often you need this test based on your health status. People with kidney disease or risk factors (like diabetes or high blood pressure) may need it more frequently.
Can diet or exercise affect creatinine levels?
Dietary protein intake can influence creatinine levels, but the impact is usually small. Exercise may slightly lower levels due to increased muscle use, but it’s not a major factor in most cases.
  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