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Serum/Plasma Creatinine Concentration (Substance 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 by measuring waste in your blood."]

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

Key facts at a glance

LOINC
63353-7
Short code
ENA SM Ab Fld Ql IA
Synonyms
ENA SM Ab 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
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 levels can indicate how efficiently your kidneys are working. High levels may suggest kidney damage or disease, while low levels could signal dehydration or other conditions affecting fluid balance.

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 involves drawing blood from a vein. Stay hydrated unless instructed otherwise.

What Happens During the Test

A healthcare provider will insert a small needle into your arm to draw blood. The sample is then sent to a lab for analysis. If a urine test is performed, you’ll collect a midstream urine sample in a clean container.

What the Results Mean

Results are compared to a standard range for your age, sex, and overall health. Abnormally high or low levels may prompt further evaluation, such as additional kidney function tests or imaging.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine

Frequently asked questions

How often should I get this test?
Your doctor will determine the frequency based on your health status. Regular tests may be recommended if you have a history of kidney problems, diabetes, high blood pressure, or other conditions that affect kidney function.
What causes creatinine levels to be too high?
High creatinine levels can result from reduced kidney function, dehydration, severe muscle damage, or certain medications. Chronic conditions like diabetes or heart disease may also contribute.
What causes creatinine levels to be too low?
Low creatinine levels may indicate dehydration, overhydration, or conditions affecting muscle mass (e.g., malnutrition or muscle wasting). Rarely, it could signal underlying metabolic disorders.
  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