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Serum or Plasma Creatinine Concentration (Qualitative/Quantitative Screening)

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 check kidney function by detecting waste products in your blood."]

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

Key facts at a glance

LOINC
43546-1
Short code
Deprecated Finger.2nd-R XR GE 3V
Synonyms
Deprecated Finger.2nd-R XR GE 3V
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
xr
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 well your kidneys are working. Kidneys filter waste like creatinine from your blood. If levels are too high, it may signal kidney problems, including reduced kidney function or disease.

What to Expect Before the Test

No special preparation is needed for this test. You may have blood drawn from a vein in your arm. If you’re having a 24-hour urine test (not applicable here), you’d collect urine over 24 hours. Avoid excessive exercise or dehydration before testing.

What the Results Mean

Results are typically reported as a concentration (e.g., milligrams per deciliter, mg/dL). Higher than normal levels may suggest kidney issues, while very low levels could indicate muscle disorders or dehydration. Your doctor will interpret results based on your overall health.

Common Causes of Abnormal Results

High creatinine levels may be due to kidney disease, dehydration, severe muscle breakdown, or conditions like heart failure. Low levels might be linked to muscle wasting, liver disease, or dehydration. Always discuss results with your healthcare provider.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Creatinine Level Check

Frequently asked questions

How often do I need this test?
Your doctor may order this test periodically to monitor kidney function, especially if you have a history of kidney issues, diabetes, high blood pressure, or other health conditions. Frequency depends on your medical needs.
What if my results are out of the normal range?
If your results are abnormal, your doctor will investigate further, possibly with additional tests or a follow-up visit. They may recommend lifestyle changes, medications, or more frequent monitoring based on your findings.
Can I eat or drink before this test?
For a standard blood test, you can eat and drink normally. If you’re doing a 24-hour urine test (not applicable here), follow your doctor’s instructions for diet and fluid intake.
  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