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Serum 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 serum. It helps assess how well your kidneys are filtering blood.

Quick summary

["A creatinine test checks kidney function by tracking waste removal."]

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

Key facts at a glance

LOINC
45007-2
Short code
C trach Ab Ser IA-aCnc
Synonyms
C trach Ab Ser IA-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
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 levels can indicate how effectively your kidneys are working. High levels may signal kidney problems, while low levels could suggest dehydration or muscle breakdown.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the draw if your doctor specifies it. Wear comfortable clothing and plan to stay for about 15 minutes.

How the Test Works

A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where it’s analyzed to measure creatinine concentration using a specialized chemical method.

Common Causes of Abnormal Results

Elevated creatinine may result from kidney disease, dehydration, or severe muscle injury. Lower levels might occur with overhydration or certain medications. Always discuss symptoms with your doctor.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Serum Creatinine

Frequently asked questions

What does a high creatinine level mean?
A high creatinine level often signals impaired kidney function, though it can also be influenced by factors like muscle mass or hydration status. Your doctor will consider your overall health and other test results to interpret results accurately.
What does a low creatinine level mean?
Low creatinine levels may suggest dehydration, overhydration, or conditions that reduce muscle mass. It’s not always a cause for concern unless accompanied by other symptoms or medical history.
How often should I get this test?
Your doctor will determine how often you need this test based on your health condition, medical history, and symptoms. Regular monitoring may be recommended if you have kidney disease, diabetes, or other chronic conditions.
  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