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C-reactive protein (CRP) by nephelometry (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 or autoimmune diseases."]

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

Key facts at a glance

LOINC
83016-6
Short code
XR Abd GE 3V AP+oblique+cone
Synonyms
XR Abd GE 3V AP+oblique+cone
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
xr
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 Might You Need This Test?

Your doctor may order this test to check for signs of inflammation, monitor chronic conditions (such as heart disease or arthritis), or evaluate responses to treatments. It can also help identify infections or other inflammatory processes in your body.

What Does a High or Low CRP Level Mean?

Elevated CRP levels often indicate inflammation or infection. While high levels can signal conditions like infections, autoimmune diseases, or heart problems, they don’t always point to a specific diagnosis. Low levels may suggest reduced inflammation, but they don’t rule out other conditions.

How Is This Test Performed?

A blood sample is taken from a vein, usually in your arm. The blood is processed to separate plasma, which is then analyzed using a nephelometry method to measure CRP levels.

What Are Common Uses?

This test is commonly used to monitor chronic inflammatory diseases, assess infection risk, evaluate treatment effectiveness, and guide decisions about further medical care.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP Plasma

Frequently asked questions

What does a CRP test tell me about my health?
A CRP test gives you a snapshot of inflammation in your body but doesn’t diagnose a specific condition. It’s often used alongside other tests and symptoms to help your doctor understand whether inflammation is present and guide treatment decisions.
How often should I get a CRP test?
Your doctor will determine how often you need this test based on your medical history, current health, and treatment plan. Regular monitoring may be recommended for conditions like heart disease, arthritis, or other chronic inflammatory diseases.
Can lifestyle changes affect CRP levels?
Yes, lifestyle factors such as diet, exercise, stress management, and smoking can influence CRP levels. Reducing inflammation through healthy habits may lower CRP, but results depend on individual health and underlying 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