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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 produced by your liver in response to inflammation in your body.

Quick summary

["CRP helps doctors assess inflammation, often used to monitor conditions like infections, autoimmune diseases, or after surgery."]

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

Key facts at a glance

LOINC
110873-7
Short code
EBV VCA IgG Msmt CSF
Synonyms
EBV VCA IgG Msmt CSF
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 a CRP test to check for signs of inflammation, monitor chronic conditions like arthritis or heart disease, or evaluate symptoms such as fever, pain, or swelling. It can also help determine if an infection is present or if your body is reacting to an injury or illness.

What Does a High or Low CRP Level Mean?

A high CRP level often indicates inflammation or infection. While not specific to any single condition, it can guide treatment decisions. A low CRP level may suggest reduced inflammation, but it doesn’t rule out other possible causes of symptoms.

How Is the Test Performed?

A blood sample is drawn from a vein, usually in your arm. The blood is then sent to a lab where it is analyzed using nephelometry, a method that measures how much light is scattered by particles in the sample, such as CRP.

What Are Common Conditions Monitored With CRP?

CRP is commonly used to monitor conditions like rheumatoid arthritis, lupus, heart disease, and infections such as pneumonia or urinary tract infections. It can also help track response to treatments for these conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

CRP plays a key role in identifying and managing inflammatory processes. While it’s not diagnostic on its own, it provides important information about whether inflammation is active. High CRP levels may prompt further testing or adjustments in treatment plans, especially for chronic inflammatory diseases or after acute events like heart attacks or surgeries.

Short name

CRP (Nephelometry)

Frequently asked questions

What does a CRP test measure exactly?
A CRP test measures the concentration of C-reactive protein in your blood. This protein is produced by your liver in response to inflammation or injury, helping your immune system identify and clear harmful substances.
Can CRP levels change with diet or exercise?
Yes, lifestyle factors like diet, exercise, and smoking can influence CRP levels. For example, a healthy diet and regular physical activity may help lower CRP, while poor diet, obesity, or smoking can increase it.
Is CRP the same as a white blood cell count?
No, CRP is a protein marker for inflammation, while a white blood cell count measures the number of immune cells in your blood. Both can be useful, but they serve different purposes in diagnosing and managing health conditions.
  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