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C-reactive protein (CRP) concentration in serum/plasma

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

This test measures the level of C-reactive protein, a protein produced by the liver in response to inflammation in your body.

Quick summary

["CRP helps identify and monitor inflammation, often used to assess infection, autoimmune conditions, or other inflammatory diseases."]

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

Key facts at a glance

LOINC
3193-0
Short code
Fact V Act/Nor PPP
Synonyms
Fact V Act/Nor PPP
Category
chemistry
Sample
plasma
Container
Lavender-top (EDTA) or Green-top (Heparin)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
coag
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 conditions like rheumatoid arthritis, infections, or heart disease, or evaluate responses to treatments.

What to Expect Before the Test

No special preparation is needed. You may have blood drawn from a vein in your arm, or if testing urine, you’ll collect a sample in a container.

What the Results Mean

Higher than normal levels may indicate inflammation, infections, or certain diseases. Lower levels might suggest reduced inflammation, but results depend on your overall health and medical history.

Common Conditions Monitored

This test is often used to monitor conditions such as infections (like pneumonia or sepsis), autoimmune diseases (like lupus or rheumatoid arthritis), or to evaluate heart health before or after procedures.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (Serum/Plasma)

Frequently asked questions

What causes CRP levels to change?
CRP levels can rise due to infections (like colds or flu), injuries, surgeries, or certain medications. They may also be higher in people with chronic conditions like heart disease or autoimmune disorders. Stress or recent illness can temporarily affect results.
How often should I get this test?
Your doctor will determine how often you need this test based on your health needs, symptoms, or ongoing treatment. Regular monitoring may be needed if you have a chronic condition or are undergoing treatment for inflammation.
Can diet or lifestyle affect CRP levels?
Yes, diet, exercise, and weight management can influence CRP levels. Reducing processed foods, increasing fruits and vegetables, and maintaining a healthy weight may help lower inflammation.
  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