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Serum or Plasma Creatinine Concentration (Standard Method)

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

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

Quick summary

["A creatinine test helps check kidney function by measuring waste product levels in your blood or urine."]

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

Key facts at a glance

LOINC
10054-5
Short code
S wave dur L-V3
Synonyms
S wave dur L-V3
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ekg
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 Is Done

Your doctor may order this test to evaluate kidney health, especially if you have symptoms like swelling, fatigue, or changes in urine output. It’s also used to monitor kidney function in people with conditions like diabetes or high blood pressure.

What to Expect Before the Test

No special preparation is needed for a blood creatinine test. For a urine test, you might be asked to collect a sample over a 24-hour period or provide a random sample. Avoid excessive exercise or dehydration before testing if instructed.

How the Test Works

Blood: A small blood sample is taken from a vein, usually in your arm. Urine: You may provide a timed urine sample (e.g., 24-hour collection) or a random sample. The lab uses a standard method to measure creatinine levels.

Possible Results and Interpretation

Results are compared to a reference range, which can vary by lab. High levels may indicate kidney problems, while low levels could suggest muscle loss or other conditions. Your doctor will discuss results in the context of your overall health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Creatinine

Frequently asked questions

What Does a High Creatinine Level Mean?
High creatinine levels often signal impaired kidney function, as the kidneys struggle to filter waste properly. This may require further testing or adjustments to medications that affect kidney function.
What Does a Low Creatinine Level Mean?
Low levels might suggest muscle atrophy, dehydration, or other conditions that reduce muscle mass or fluid balance. Your doctor will investigate further if levels are persistently low.
How Often Should I Get This Test?
Your doctor will determine the frequency based on your health needs. Regular monitoring may be recommended if you have chronic kidney disease, diabetes, or other conditions affecting 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