Skip to content

Serum Creatinine (Creatinine Level)

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

["Kidney function is evaluated by checking 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
67872-2
Short code
MEDICAREENDSTAGERENALDISEASECOVERAGEREQUESTED
Synonyms
—
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 Is This Test Done?

Your healthcare provider 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 to track kidney disease progression or response to treatment.

Who Might Need This Test?

People with risk factors for kidney problems—such as high blood pressure, diabetes, or a family history of kidney disease—may need this test. It’s also part of routine check-ups for those with chronic conditions.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the test if it’s part of a larger panel. Bring any medications you’re taking.

What Happens During the Test?

A healthcare professional will draw blood from a vein in your arm. The process is quick and typically causes mild discomfort. The sample is sent to a lab for analysis.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

High creatinine levels may indicate poor kidney function, while very low levels could suggest overhydration or kidney damage. Elevated levels often prompt further testing to diagnose or manage kidney disease.

Short name

Creatinine

Frequently asked questions

What Does a High Creatinine Level Mean?
A high creatinine level may signal that your kidneys aren’t working as well as they should, which could be due to conditions like kidney disease, dehydration, or heart problems. Your doctor will discuss next steps based on your overall health.
What If My Creatinine Level Is Normal?
A normal level doesn’t guarantee healthy kidneys, but it suggests your kidneys are filtering blood effectively. Regular follow-ups may still be needed if you have risk factors for kidney issues.
Does Diet Affect Creatinine Levels?
Dietary changes like eating more protein or drinking less water can temporarily affect creatinine levels, but your doctor will consider overall kidney health, not just this single test result.
  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