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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

["This test is often used to check how well your kidneys are working."]

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

Key facts at a glance

LOINC
51601-3
Short code
MTX 4h p SerPl-sCnc
Synonyms
MTX 4h p SerPl-sCnc
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 healthcare provider may order this test to evaluate kidney health, monitor kidney disease, or check for conditions that affect kidney function, such as dehydration, heart problems, or certain medications.

What to Expect Before the Test

No special preparation is usually needed. You may drink water before the test, but avoid eating or drinking for a few hours beforehand if instructed. Tell your doctor about any medications you’re taking, as some can affect kidney function.

How the Test Is Performed

A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where it is analyzed to measure creatinine levels.

What the Results Mean

Higher than expected creatinine levels may indicate reduced kidney function, while lower levels could suggest overhydration or other conditions. Your doctor will interpret the results in relation to your overall health and symptoms.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

None

Frequently asked questions

What does a high creatinine level mean?
A high creatinine level often signals that your kidneys are not filtering blood as well as they should, which can be linked to kidney disease, dehydration, or other health issues. Your doctor will review your results alongside other tests and symptoms to determine the cause and next steps.
Can diet affect creatinine levels?
Dietary changes like eating more protein or consuming certain medications can temporarily influence creatinine levels. However, your doctor will consider overall health factors, including diet and medications, when interpreting your results.
How often should I get this test?
Your doctor will decide how often you need this test based on your health condition, symptoms, and medical history. Regular monitoring may be recommended if you have kidney-related concerns or are taking medications that 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