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Serum or Plasma Creatinine Concentration (Qualitative or Quantitative Screening)

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

["Kidney function screening is critical for early detection of kidney problems."]

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

Key facts at a glance

LOINC
42159-4
Short code
XR ST Views
Synonyms
XR ST Views
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 efficiently your kidneys remove waste from your blood. Abnormal results may signal kidney disease or other health concerns, even if you don’t have symptoms yet.

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 a blood draw. Hydration can affect results, so drink water as directed by your provider.

Common Causes of Abnormal Results

High creatinine levels may occur due to dehydration, kidney disease, or conditions affecting muscle mass. Low levels could suggest overhydration, liver disease, or certain medications.

How Results Are Used

Your doctor may use these results to monitor kidney function, guide treatment plans, or check for conditions like chronic kidney disease or acute kidney injury.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Creatinine is a reliable marker for kidney function because it’s produced at a steady rate based on muscle mass and excreted by the kidneys. Persistently high levels often indicate declining kidney function, while low levels may warrant further investigation into hydration status or other metabolic factors.

Short name

Creatinine Level Check

Frequently asked questions

What triggers a creatinine test?
Your doctor may order this test if you have symptoms like swelling, frequent urination, fatigue, or if you have a history of kidney disease, diabetes, or high blood pressure. It’s also used during routine check-ups or before certain procedures.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on your lab. Your provider will discuss them with you during a follow-up visit.
Can diet or medications affect creatinine levels?
Yes—high-protein foods, certain medications (like NSAIDs), or dehydration can temporarily raise levels. Always inform your doctor about all medications and dietary habits before testing.
  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