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Serum or Plasma Creatinine Concentration (Mass Concentration)

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

["A creatinine test helps check kidney function by measuring waste removal efficiency."]

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

Key facts at a glance

LOINC
33086-0
Short code
GA from O-I BPD.Chitty 1997
Synonyms
GA from O-I BPD.Chitty 1997
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
us-estimated-from-o-i-bpd-chitty
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 This Test Matters

Creatinine is a byproduct of muscle breakdown and is filtered out by your kidneys. High levels may indicate kidney problems, while low levels could suggest dehydration or muscle loss. This test is often used alongside other kidney function tests to diagnose or monitor conditions like chronic kidney disease.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the test if it’s part of a broader metabolic panel. Drink plenty of water the day before to ensure accurate results.

What Happens During the Test

A healthcare provider will draw blood from a vein in your arm. The sample is sent to a lab for analysis. The test typically takes a few minutes, and you may feel slight discomfort but no lasting effects.

Possible Results and Interpretation

Results are compared to a reference range specific to your age, sex, and overall health. Elevated levels may signal kidney issues, while very low levels could raise concerns about hydration or muscle metabolism. Your doctor will discuss the results in the context of your medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine Level

Frequently asked questions

What causes high creatinine levels?
High creatinine levels can result from kidney disease, dehydration, severe muscle damage, or conditions that reduce blood flow to the kidneys. It may also appear in people with diabetes, heart failure, or certain medications that affect kidney function.
What causes low creatinine levels?
Low creatinine levels may occur in people with very little muscle mass, severe dehydration, or conditions that impair muscle metabolism. Rarely, it can also be seen in newborns or during pregnancy.
How often should I get this test?
Your doctor may recommend this test periodically if you have kidney-related conditions, diabetes, high blood pressure, or a history of kidney issues. Follow-up frequency depends on your health status and treatment plan.
  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