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Creatinine, Serum — Assay

Published: August 9, 2026Updated: August 16, 2026

A blood test that measures serum creatinine, a waste product made by the kidneys and used to assess kidney function.

Quick summary

["Serum creatinine helps evaluate how well your kidneys are filtering waste from the blood."]

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

Key facts at a glance

LOINC
62807-3
Short code
Serum creatinine assay proto
Synonyms
Serum creatinine assay proto
Category
kidney
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
0.6
Ref high
1.3
Critical range
— – 10 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
phenx
CPT
82565
SNOMED
247997009
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 is this test?

A serum creatinine test measures the amount of creatinine in your blood. Creatinine is a waste product produced when your muscles break down energy and is removed from the body mainly by the kidneys.

Why might I need this test?

Your doctor may order this test to check kidney function, monitor a kidney condition, or evaluate treatment for conditions that can affect the kidneys. It may also be included in a broader metabolic panel or used to help calculate estimated glomerular filtration rate, or eGFR.

How is the test performed?

A healthcare professional draws a blood sample from a vein, usually in your arm. The sample is sent to a laboratory, where creatinine is measured using a laboratory assay.

How do I prepare for the test?

A serum creatinine test often requires no special preparation, although fasting may be requested if it is part of a larger blood panel. Follow your doctor's instructions and tell the laboratory if you are pregnant or have recently had an illness, as these factors can affect the result.

Reference range

Adult male: 0.7-1.3 mg/dL; Female: 0.6-1.1 mg/dLN/A

Specimen: serum

No special preparation required. Stay well hydrated.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Serum creatinine

Frequently asked questions

Does a serum creatinine test require fasting?
Usually, no. Fasting may be needed if your doctor ordered creatinine as part of a broader panel that requires fasting, so follow the instructions provided with your order.
What does a high creatinine result mean?
A high level may suggest reduced kidney function, dehydration, or other factors that affect muscle breakdown or kidney filtering. Your doctor will interpret the result alongside your other tests and health history.
Is creatinine the same as eGFR?
No. Creatinine is a measured blood value, while eGFR is an estimate of kidney filtering function calculated using creatinine and other factors such as age and sex.
  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