Skip to content

C-reactive protein (CRP) by nephelometry

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

This test measures a protein in your blood that rises when your body is fighting inflammation or infection.

Quick summary

["Helps track mild to moderate inflammation, often used alongside other tests for early detection of conditions like heart disease or autoimmune disorders."]

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

Key facts at a glance

LOINC
17324-5
Short code
N men Ag CSF LA-aCnc
Synonyms
N men Ag CSF LA-aCnc
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
la
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why It’s Done

Your doctor may order this test to check for signs of inflammation, monitor chronic conditions like arthritis or heart disease, or evaluate symptoms like fever, fatigue, or joint pain that suggest infection or an immune response.

What to Expect

A small blood sample is taken from a vein, usually in your arm. The blood is sent to a lab where it’s analyzed using a sensitive measurement method to detect even small amounts of CRP.

What the Results Mean

Higher-than-normal CRP levels may indicate inflammation, but they don’t always pinpoint the exact cause. Your doctor will consider your overall health, other test results, and symptoms to interpret the findings.

Common Conditions Monitored

This test is often used to monitor conditions like rheumatoid arthritis, heart disease, or infections (e.g., pneumonia, urinary tract infections). It can also help assess how well treatments for inflammation are working.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

CRP is a marker for systemic inflammation, meaning it reflects widespread immune activity in the body. While it doesn’t diagnose a specific condition, elevated levels can signal areas for further investigation, such as infections, autoimmune diseases, or metabolic disorders.

Short name

CRP (High-Sensitivity)

Frequently asked questions

What triggers CRP levels to rise?
CRP can increase due to infections (like colds or flu), injuries, surgeries, or certain medications. It also rises in conditions like rheumatoid arthritis, lupus, or heart disease. Stress and smoking may also play a role.
How often should I get this test?
Your doctor will determine the frequency based on your health needs. Some people get it yearly to monitor chronic conditions, while others may need it more often if symptoms change or if you’re being treated for an active issue.
Can diet or lifestyle affect CRP levels?
Yes! Eating a heart-healthy diet, staying active, and managing stress can help lower CRP levels. Avoiding smoking and limiting alcohol may also support better inflammation control.
  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