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C-reactive protein (CRP) measured by chemiluminescent immunoassay (CLIA) in 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 track inflammation, often used to monitor conditions like infections, autoimmune diseases, or after surgery."]

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

Key facts at a glance

LOINC
70164-9
Short code
C trach+GC pnl Vag NAA+probe
Synonyms
C trach+GC pnl Vag NAA+probe
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
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 doctor may order this test to check for signs of inflammation, monitor chronic conditions like rheumatoid arthritis or heart disease, or evaluate your response to treatment. It can also help identify infections or assess risk for future health issues.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the test if instructed. Bring your test results or questions to your appointment.

What the Results Mean

Higher-than-normal CRP levels may indicate inflammation, infections, or certain diseases. Lower levels suggest reduced inflammation. Your doctor will interpret results in the context of your overall health and medical history.

Common Conditions Monitored

Elevated CRP is often seen in conditions like infections (e.g., pneumonia, urinary tract infections), autoimmune diseases (e.g., lupus, rheumatoid arthritis), or after trauma/surgery. It can also signal heart disease risk or response to treatment.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (Plasma)

Frequently asked questions

What causes CRP levels to rise?
CRP levels can increase due to infections (bacterial, viral), injuries, surgeries, autoimmune diseases (like arthritis), or certain medications. Stress, smoking, or obesity may also influence results.
How often should I get this test?
Your doctor will determine the frequency based on your condition. Some patients get CRP tests every few months (e.g., for heart disease monitoring), while others may need it only occasionally.
Can diet or lifestyle affect CRP levels?
Yes—diet high in processed foods, sugar, or unhealthy fats may raise CRP. Regular exercise, a balanced diet, and managing stress can help lower inflammation and CRP levels 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