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Serum or plasma concentration of C-reactive protein (CRP)

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

This test measures the amount of C-reactive protein in your blood. CRP is a protein produced by your liver in response to inflammation.

Quick summary

["CRP helps track inflammation in your body, 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
25778-2
Short code
GH 50M p chal SerPl-sCnc
Synonyms
GH 50M p chal SerPl-sCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 a CRP test to check for signs of inflammation, monitor chronic conditions like rheumatoid arthritis or lupus, or evaluate symptoms such as fever, joint pain, or unexplained fatigue. It can also help assess the risk of heart disease or other inflammatory disorders.

What to Expect During the Test

A blood sample is taken from a vein, usually in your arm. You may feel a slight pinch, but it typically doesn’t cause significant discomfort. The sample is sent to a lab for analysis. Results are usually available within a few days.

Common Conditions Monitored

CRP is commonly used to monitor conditions involving inflammation, such as infections, autoimmune diseases (e.g., rheumatoid arthritis, lupus), or inflammatory bowel disease. It can also help evaluate heart health and response to treatments.

What the Results Mean

Higher CRP levels may indicate inflammation, but they can also be influenced by factors like infection, stress, or certain medications. Your results will be interpreted by your healthcare provider in the context of your overall health and symptoms.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CRP serves as a general marker for inflammation in the body. Elevated levels can signal an ongoing inflammatory process, which may guide treatment decisions or help assess the effectiveness of therapies. However, CRP alone cannot diagnose specific conditions—it’s often used alongside other tests and clinical findings.

Short name

CRP Level

Frequently asked questions

What causes CRP levels to be higher than usual?
CRP levels can rise due to infections (like colds or flu), injuries, surgeries, or certain medications. Chronic conditions such as arthritis, heart disease, or autoimmune disorders may also lead to elevated CRP. Stress, smoking, or obesity can sometimes affect CRP levels as well.
How often should I get this test?
Your healthcare provider will determine how often you need this test based on your medical history, symptoms, and treatment plan. Some people may need CRP checked regularly (e.g., every few months) to monitor chronic conditions, while others may only need it once.
Can diet or lifestyle changes affect CRP levels?
Yes, lifestyle factors like diet (e.g., Mediterranean diet), exercise, and weight management can influence CRP levels. Reducing inflammation through healthy habits may help lower CRP, but results depend on overall health and medical 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