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

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

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

Quick summary

["CRP helps your doctor assess inflammation in your body."]

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

Key facts at a glance

LOINC
5096-3
Short code
C immitis Ab Titr Ser CF
Synonyms
C immitis Ab Titr Ser CF
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
comp-fix
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 This Test Is Done

Doctors may order a CRP test to check for signs of inflammation, monitor conditions like infections, autoimmune diseases, or heart disease, or evaluate responses to treatments. It can also help identify risks for certain health issues before symptoms appear.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm to draw blood. If you’re on blood thinners, let your doctor know before the test.

What the Results Mean

Higher than normal CRP levels may indicate inflammation, infections, or other health problems. Lower levels suggest less inflammation. Your doctor will interpret results based on your medical history and symptoms.

Common Conditions Monitored

CRP is often used to monitor conditions like rheumatoid arthritis, lupus, heart disease, or to check for infections such as pneumonia or sepsis.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

CRP plays a key role in identifying and managing inflammatory processes, helping doctors tailor treatments and track disease progression or response to therapy.

Short name

CRP Level

Frequently asked questions

What causes CRP levels to change?
CRP levels can rise due to infections, injuries, autoimmune diseases, or certain medications. They may also drop if inflammation decreases, such as after treatment for an illness.
Can diet or exercise affect CRP levels?
Yes, lifestyle factors like diet (e.g., Mediterranean diet), exercise, and weight management can influence CRP levels. Reducing inflammation may lower CRP over time.
Is CRP testing painful?
The blood draw itself is usually mild discomfort, but most people tolerate it well. If you’re anxious, ask your doctor about numbing cream or other options.
  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