Skip to content

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

["Kidney function check with a simple blood test."]

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

Key facts at a glance

LOINC
31626-5
Short code
ENA SS-B IgG Ser Ql
Synonyms
ENA SS-B IgG Ser Ql
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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 Is This Test Done?

Doctors may order this test to evaluate kidney function, monitor chronic kidney disease, check for kidney-related conditions, or assess overall health before certain procedures. High levels may indicate kidney problems, while low levels could suggest dehydration or muscle breakdown.

What Does a High or Low Result Mean?

Results can vary based on individual health, diet, and medications. High creatinine levels often signal impaired kidney function, while very low levels may require further investigation to rule out other causes like dehydration or muscle disorders.

How Is This Test 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 concentration using a specialized method, such as enzymatic or spectrophotometric techniques.

What Can Affect Test Results?

Several factors can influence creatinine levels, including recent exercise, dehydration, certain medications (e.g., contrast dyes for imaging), and dietary habits (e.g., high-protein meals). Always inform your healthcare provider about any changes in your routine.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Creatinine

Frequently asked questions

How often should I get this test?
The frequency depends on your health condition. Healthy adults may not need regular testing unless advised by a doctor. People with kidney disease, diabetes, or hypertension may need monitoring more often, often every few months or annually.
Can I eat or drink before this test?
Typically, no special preparation is needed. However, if you are taking contrast dyes for imaging, your doctor may instruct you to stop certain medications or fluids beforehand. Always follow your healthcare provider’s instructions.
Are there any risks or side effects?
The most common risk is a mild bruise or slight pain at the needle insertion site. Rarely, there may be a reaction to the blood draw, such as fainting or swelling. Most side effects are minor and temporary.
  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