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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, infection, or injury.

Quick summary

["High CRP levels may signal inflammation needing further evaluation by your healthcare provider."]

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

Key facts at a glance

LOINC
111424-8
Short code
FLUBV Ab Msmt Ser
Synonyms
FLUBV Ab Msmt Ser
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 Is This Test Done?

Your doctor may order this test to check for signs of inflammation, monitor conditions like arthritis, heart disease, or infections, or assess how your body responds to treatments for these conditions.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours if your blood is drawn early in the morning for more accurate results.

What Happens During the Test?

A healthcare professional will draw blood from a vein in your arm. The blood sample is then analyzed to measure CRP levels using a specialized nephelometry method.

What Are Possible Results?

Results are reported in milligrams per liter (mg/L). Higher-than-normal levels may indicate inflammation, while very low levels might suggest reduced immune response or certain medical conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (High-Sensitivity)

Frequently asked questions

What Does a High CRP Level Mean?
A high CRP level may signal inflammation, but it doesn’t always pinpoint the exact cause. Your doctor will use these results alongside other tests and symptoms to guide diagnosis and treatment.
Can Diet or Exercise Affect CRP Levels?
Yes, lifestyle factors like diet, exercise, and stress can influence CRP levels. Reducing inflammation through healthy eating, regular activity, and managing stress may help lower CRP over time.
Is CRP Test Painful?
The blood draw itself may cause mild discomfort or bruising, but the procedure is quick and usually well-tolerated. Most people experience minimal pain afterward.
  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