Skip to content

C-reactive protein (CRP) by nephelometry (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.

Quick summary

["CRP helps track inflammation in your body."]

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

Key facts at a glance

LOINC
63394-1
Short code
ENA Jo1 Ab CSF IA-aCnc
Synonyms
ENA Jo1 Ab CSF IA-aCnc
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order CRP testing to check for signs of inflammation, monitor conditions like infections, autoimmune diseases, or heart disease, or evaluate responses to treatments.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into a vein (usually in your arm) to draw blood. If you’re on blood thinners, inform your provider beforehand.

What the Results Mean

Elevated CRP levels often indicate inflammation, but they can also be influenced by factors like infection, injury, or certain medications. Your results will be interpreted by your healthcare team based on your overall health.

Common Conditions Monitored

CRP is commonly used to monitor conditions such as rheumatoid arthritis, lupus, heart disease, or infections like pneumonia or sepsis.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CRP is a marker for systemic inflammation. While it doesn’t diagnose specific conditions, it helps guide treatment decisions and assess disease activity or treatment effectiveness.

Short name

CRP (NONE)

Frequently asked questions

What does a high CRP level mean?
A high CRP level suggests inflammation is present in your body. It could be due to infections, autoimmune diseases, or other inflammatory conditions. Your doctor will discuss this with you in detail.
Can diet or exercise affect CRP levels?
Yes, lifestyle factors like diet, exercise, and weight can influence CRP levels. Eating a heart-healthy diet, staying active, and managing stress may help lower inflammation over time.
Is CRP testing painful?
The blood draw itself is typically mild discomfort, but most people describe it as no worse than a small pinch. Recovery is usually quick, and most people don’t experience lasting effects.
  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