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Serum or Plasma Mass Concentration of Creatinine

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 kidney function.

Quick summary

["A creatinine test helps check how well your kidneys are filtering waste from your blood."]

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

Key facts at a glance

LOINC
74541-4
Short code
SFTPD Ser-mCnc
Synonyms
SFTPD Ser-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 This Test Is Done

Your doctor may order this test to evaluate kidney health, monitor kidney disease, or check for conditions that affect how your kidneys work, such as diabetes or high blood pressure. It can also be used to assess kidney function before certain surgeries or treatments.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it involves a blood draw, but this is not always required for creatinine alone. Drink plenty of fluids the day before if you have questions about hydration.

What Happens During the Test

A healthcare provider will take a blood sample from a vein in your arm. You may feel a slight pinch, but it usually doesn’t cause discomfort. The sample is then sent to a lab for analysis.

What the Results Mean

Results are compared to a reference range, which can vary by lab. Higher than expected levels may indicate reduced kidney function, while lower levels could suggest muscle loss or overhydration. Your doctor will interpret results in the context of your overall health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Creatinine levels are a key marker for kidney function. Elevated levels often signal impaired kidney filtration, which can lead to complications like fluid buildup, electrolyte imbalances, or even kidney failure if untreated. Regular monitoring helps manage chronic kidney disease and other conditions affecting kidney health.

Short name

Creatinine Level

Frequently asked questions

What causes creatinine levels to be higher than normal?
Several factors can influence creatinine levels, including dehydration, muscle mass, certain medications, or kidney disease. Conditions like diabetes or heart failure may also affect kidney function, indirectly raising creatinine. Always discuss symptoms or concerns with your doctor.
How often should I get this test?
Your doctor will determine how often you need this test based on your health status. People with kidney disease or risk factors (like diabetes or high blood pressure) may need it more frequently, while others may only need it occasionally.
Can diet affect creatinine levels?
Dietary changes alone won’t significantly alter creatinine levels, but protein intake (especially from animal sources) can influence muscle mass, which may indirectly affect results. Hydration status is more directly tied to creatinine levels—drinking enough water helps maintain normal 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