Skip to content

C-reactive protein (CRP) concentration, mass concentration in 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 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
75394-7
Short code
Chr UpDi Amn/CVS
Synonyms
Chr UpDi Amn/CVS
Category
chemistry
Sample
fluid
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
molgen
Specimen volume
2-5 mL
Stability
Room temperature: 2h, Refrigerated: 24h
Hemolysis max
300
TAT
4–24 hours
Order
routine

What Is C-Reactive Protein (CRP)?

C-reactive protein (CRP) is a marker produced by your liver when your body is fighting inflammation. It rises in response to infections, injuries, or conditions causing inflammation, such as arthritis or heart disease. CRP doesn’t directly indicate the cause but helps track overall inflammation levels.

Why Might You Need This Test?

Doctors may order CRP tests to monitor chronic conditions like rheumatoid arthritis, heart disease, or inflammatory bowel disease. It’s also used to check for infections, evaluate post-surgery recovery, or assess risk for conditions like cardiovascular disease.

When Is CRP Tested?

CRP is often tested as part of routine check-ups, especially if you have a history of inflammation or heart problems. It may also be done before surgeries, during flare-ups of autoimmune diseases, or to monitor treatment effectiveness.

What Does a High CRP Level Mean?

Elevated CRP levels suggest inflammation is present. While high CRP can signal infections, injuries, or autoimmune activity, it doesn’t pinpoint the exact cause. Persistently high levels may prompt further testing to identify underlying conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

CRP plays a key role in diagnosing and managing inflammatory diseases. It’s a simple blood test that helps doctors assess risk for conditions like heart disease or infections, guiding treatment plans and monitoring progress over time.

Short name

CRP

Frequently asked questions

What triggers CRP levels to rise?
CRP levels rise in response to infections (like pneumonia or urinary tract infections), injuries, surgeries, or conditions causing chronic inflammation (e.g., rheumatoid arthritis, lupus). Stress, smoking, or certain medications may also influence CRP levels.
How soon after an event (like surgery or infection) might CRP levels change?
CRP levels typically rise within days of an inflammatory event and may peak in 3–5 days before gradually returning to normal over weeks. Results can vary based on the cause and individual health.
Can CRP levels be affected by diet or lifestyle?
Yes, diet, exercise, smoking, and weight can influence CRP levels. Reducing inflammation through healthy eating, regular activity, and avoiding smoking may help lower CRP 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