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C-reactive protein, mass concentration (serum/plasma)

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

This test measures the level of C-reactive protein, a protein produced by the liver in response to inflammation or infection in the body.

Quick summary

["CRP helps doctors assess inflammation and guide treatment for conditions like infections, autoimmune diseases, or heart disease."]

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

Key facts at a glance

LOINC
16764-3
Short code
DDE Bld-mCnc
Synonyms
DDE Bld-mCnc
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your doctor may order CRP testing to monitor inflammation, check for infections, evaluate autoimmune conditions, or assess risk for heart disease. It can also help determine how well a treatment is working for conditions like arthritis or other inflammatory disorders.

What Does a High or Low CRP Level Mean?

High CRP levels often signal inflammation, infections, or autoimmune activity. Low levels may indicate no active inflammation, but they don’t rule out all causes of illness. Your doctor will interpret results in the context of your symptoms and other tests.

Common Conditions Monitored With CRP

CRP is commonly used to monitor conditions like rheumatoid arthritis, lupus, or other autoimmune diseases. It may also help track infections, heart disease risk, or response to treatments for inflammatory conditions.

What to Expect During the Test

A blood sample is drawn from a vein, usually in your arm. You may feel a small pinch, but it’s quick and doesn’t require special preparation. Results are typically ready within a few days.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CRP’s Role in Healthcare

Short name

CRP (Serum/Plasma)

Frequently asked questions

How long does it take to get CRP test results?
Results are usually available within 24 to 48 hours, depending on your lab’s processing time. Your doctor will discuss them with you during your follow-up visit.
Can CRP levels change with diet or exercise?
While diet and exercise can influence inflammation, CRP levels alone don’t reflect overall health. Your doctor will consider lifestyle factors alongside test results to guide care.
Is CRP testing painful or uncomfortable?
The blood draw is brief and may cause mild discomfort, but it’s not usually painful. Most people tolerate it well, and any soreness fades quickly.
  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