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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 made by your liver in response to inflammation or infection.

Quick summary

["CRP helps track inflammation, often used to monitor conditions like arthritis or infections."]

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

Key facts at a glance

LOINC
41843-4
Short code
LCMV IgG+IgM Pnl Titr CSF IF
Synonyms
LCMV IgG+IgM Pnl Titr CSF IF
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
if
CPT
82784
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 this test to check for signs of inflammation, monitor chronic conditions like arthritis or heart disease, or evaluate responses to treatments. High levels may indicate infections, autoimmune diseases, or other inflammatory processes.

What Does a High or Low Level Mean?

Elevated CRP levels often signal inflammation, but they can also be normal in some cases (e.g., after injury or infection). Low levels may suggest reduced inflammation, but they don’t always mean you’re healthy—other factors can affect results.

Common Conditions Monitored

This test is commonly used to monitor conditions like rheumatoid arthritis, heart disease, or infections. It may also help assess how well a treatment is working for inflammatory diseases.

Sample Collection & Preparation

A blood sample is taken from a vein, usually in your arm. The blood is sent to a lab where it’s analyzed using a nephelometry method to measure CRP levels precisely.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CRP is a marker for inflammation, but it’s not specific to any single condition. High levels can appear with infections, autoimmune diseases, or other inflammatory processes. It’s often used alongside other tests for a fuller picture.

Short name

CRP (High Sensitivity)

Frequently asked questions

What causes CRP levels to change?
CRP levels can rise due to infections (like pneumonia or urinary tract infections), injuries, surgeries, or certain medications. They may also be higher in people with autoimmune diseases (e.g., lupus) or heart disease. Stress or recent illness can temporarily affect results.
How long does it take to get results?
Results are typically available within 24 to 48 hours, depending on your lab’s processing time. Your provider will discuss the results with you during your follow-up visit.
Can diet or exercise affect CRP levels?
Yes, lifestyle factors like diet, exercise, and smoking can influence CRP levels. Eating a heart-healthy diet, staying active, and avoiding smoking may help lower inflammation over time.
  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