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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

["Your kidneys filter waste from blood; this test checks kidney function by measuring creatinine levels."]

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

Key facts at a glance

LOINC
36073-5
Short code
MR Scrotum+Test
Synonyms
MR Scrotum+Test
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
mr
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

What Does This Test Measure?

Creatinine is a byproduct of muscle breakdown and is naturally excreted by the kidneys. Elevated levels may indicate impaired kidney function, while lower levels could suggest muscle underuse or other conditions.

Why Is This Test Done?

Doctors order this test to monitor kidney health, especially in patients with diabetes, high blood pressure, or a history of kidney disease. It’s also used to assess kidney function before certain procedures or medications.

How Is the Sample Collected?

A blood sample is taken from a vein, usually in your arm. You may feel a brief pinch, but it’s quick and painless. No special preparation is needed.

What Are Common Results?

Results are compared to a general reference range, but individual values can vary based on factors like age, sex, and muscle mass. High levels may signal kidney issues, while very low levels may warrant further investigation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine

Frequently asked questions

Why might my creatinine level be higher than expected?
Possible reasons include dehydration, muscle injury, certain medications, or kidney problems. Your doctor will review your medical history and other test results to determine the cause.
Could my diet affect my creatinine test results?
Eating high-protein foods or drinking large amounts of water can temporarily influence creatinine levels. Your doctor may advise avoiding extreme dietary changes before testing if needed.
What if my creatinine level is out of the normal range?
If your results are abnormal, your healthcare provider will discuss next steps, which may include additional tests, lifestyle changes, or monitoring. Follow-up may depend on your overall health and symptoms.
  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