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Serum Creatinine (Creatinine)

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

This test measures the amount of creatinine, a waste product from muscle metabolism, in your blood serum. It helps assess how well your kidneys are filtering blood.

Quick summary

["Kidney function depends on this test to detect early kidney problems."]

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

Key facts at a glance

LOINC
108911-9
Short code
PS IgA Msmt Ser
Synonyms
PS IgA Msmt Ser
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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 doctor may order this test to check for kidney disease, monitor kidney function before or after treatments, or evaluate symptoms like swelling, fatigue, or changes in urine output. It’s also used in certain medical conditions like heart disease or dehydration.

What Does a High or Low Level Mean?

High levels may indicate kidney problems, fluid overload, or conditions like heart failure. Low levels are less common but could suggest muscle breakdown or certain liver/kidney disorders.

How Is the Test Performed?

A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where creatinine is measured using an automated method that detects waste products in your blood.

What Should You Do Before the Test?

No special preparation is needed, but inform your doctor about any medications, recent illnesses, or conditions that might affect results (e.g., severe dehydration, muscle injury).

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine Level

Frequently asked questions

Will I feel any pain or discomfort during the blood draw?
You may feel a slight pinch or sting when the needle is inserted, but it usually goes away quickly. Most people experience minimal discomfort afterward.
Can diet or exercise affect my creatinine levels?
Dietary protein intake can influence creatinine levels, but short-term changes are unlikely to impact results. Exercise itself does not directly alter creatinine levels, but intense muscle activity (e.g., heavy lifting) may temporarily raise them.
What if my results are outside the expected range?
If your results are abnormal, your doctor will discuss them with you and may recommend additional tests or lifestyle adjustments. Follow-up may include monitoring kidney function over time.
  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