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Serum/Plasma Creatinine Concentration (Mass)

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

This test measures the amount of creatinine, a waste product from muscle metabolism, in your blood or plasma. 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
58883-0
Short code
GH sp22 SerPl-mCnc
Synonyms
GH sp22 SerPl-mCnc
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 doctor may order this test to check for kidney disease, monitor kidney function over time, or evaluate symptoms like swelling, fatigue, or changes in urine output. It’s also used before certain procedures or medications that affect kidney health.

What to Expect Before the Test

No special preparation is needed unless instructed. You may drink water beforehand to help your kidneys produce urine, but avoid excessive fluids or foods high in salt or protein 24 hours before testing.

What Happens During the Test

A healthcare provider will draw blood from a vein in your arm. You may feel a slight pinch, but it usually takes only a few minutes. If you’re tested for urine, you’ll collect a sample in a clean container.

What the Results Mean

Results help determine if your kidneys are working properly. High levels may indicate kidney disease or other health issues, while very low levels could signal muscle disorders or liver problems. Your doctor will discuss these results with you.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine Level

Frequently asked questions

How often should I get this test?
Your doctor will decide how often based on your health history, symptoms, and other tests. Regular monitoring may be needed if you have kidney disease, diabetes, or high blood pressure.
Can diet affect my creatinine levels?
Yes, eating too much protein or salt can temporarily raise creatinine levels. Avoiding excessive protein for a day or two before testing can help get a more accurate result.
What if my results are outside the normal range?
If your results are abnormal, your doctor will review them with you and may recommend further tests or treatments. They’ll also check for other conditions that could affect kidney function.
  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