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C-reactive protein (CRP) concentration, plasma

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

This test measures the level of C-reactive protein in your blood plasma, a marker often used to assess inflammation or infection.

Quick summary

["CRP helps doctors track inflammation, which may signal infections, autoimmune conditions, or other health concerns."]

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

Key facts at a glance

LOINC
111903-1
Short code
Num apprch deep cannl BD+PD Endscpy
Synonyms
Num apprch deep cannl BD+PD Endscpy
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
endoscopy
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 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 symptoms such as fever, pain, or swelling that could indicate infection or an immune response.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into a vein (usually in your arm) to draw blood. If you’re nervous, let your provider know—they can offer comfort measures.

What the Results Mean

Higher-than-normal CRP levels may suggest inflammation, infection, or certain diseases. Lower levels might indicate reduced inflammation. Your provider will interpret results in the context of your symptoms and medical history.

Common Conditions Monitored

This test is often used to monitor conditions like rheumatoid arthritis, lupus, heart disease, or infections such as pneumonia or sepsis. It can also help guide treatment decisions for conditions like inflammatory bowel disease.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (Plasma)

Frequently asked questions

What does a high CRP level mean?
A high CRP level often signals inflammation in your body, which can be caused by infections, autoimmune diseases, or other health issues. Your provider will discuss the results with you and may recommend additional tests to find the cause.
How often should I get this test?
Your provider will determine how often you need this test based on your health needs. Some people get it yearly for routine checks, while others may need it more frequently if they have a chronic condition or symptoms of inflammation.
Can diet or exercise affect CRP levels?
Yes, lifestyle factors like diet, exercise, and smoking can influence CRP levels. Eating a balanced diet, staying active, and avoiding smoking may help lower inflammation and support better 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