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C-reactive protein, serum/plasma concentration (qualitative screening)

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

This test measures the level of C-reactive protein (CRP) in your blood, a marker often checked to assess inflammation or infection.

Quick summary

["CRP helps doctors monitor inflammation, infection risk, or response to treatment."]

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

Key facts at a glance

LOINC
31301-5
Short code
C pneum IgG CSF-aCnc
Synonyms
C pneum IgG CSF-aCnc
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 this test to check for signs of inflammation, infections (like pneumonia or sepsis), autoimmune conditions, or to evaluate how well you’re responding to treatment for conditions such as arthritis or heart disease.

What Does a High or Low Level Mean?

Elevated CRP levels often indicate inflammation or infection, but they can also be raised due to other factors like stress, certain medications, or chronic conditions. Low levels may suggest no active inflammation, but they don’t rule out all causes.

How Is This Test Performed?

A blood sample is drawn from a vein, usually in your arm. The blood is then sent to a lab where it’s analyzed to measure CRP levels using a sensitive detection method.

What Are Common Results?

Results are reported as qualitative (qualitative screening), meaning they’re categorized as elevated or not elevated rather than providing a specific numeric value. Your doctor will interpret the result in the context of your symptoms and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

CRP is a non-specific marker that can signal inflammation in the body. While it’s not definitive for diagnosing conditions like infections or autoimmune diseases, it’s useful for monitoring trends, guiding treatment decisions, and assessing risk for conditions like cardiovascular disease. Always discuss results with your healthcare provider.

Short name

CRP (Screen)

Frequently asked questions

What Does a Positive or Elevated CRP Mean?
An elevated CRP level suggests there may be inflammation or infection in your body, but it doesn’t pinpoint the exact cause. Your doctor will consider other tests and your symptoms to determine the next steps.
Can CRP Levels Change Over Time?
Yes, CRP levels can fluctuate based on your health status, recent infections, medications, or other factors. Regular monitoring may be needed if you have ongoing conditions like arthritis or heart disease.
Does Diet or Lifestyle Affect CRP Levels?
Yes, certain lifestyle factors like diet, exercise, smoking, and stress can influence CRP levels. Maintaining a healthy lifestyle may help keep inflammation in check, but CRP alone doesn’t determine overall health.
  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