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C-reactive protein (CRP) in plasma or serum by turbidimetry

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

This test measures a protein called C-reactive protein, which your body produces in response to inflammation or infection.

Quick summary

["CRP helps track inflammation levels in your blood."]

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

Key facts at a glance

LOINC
70162-3
Short code
C trach+GC pnl Urth NAA+probe
Synonyms
C trach+GC pnl Urth 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 healthcare provider may order this test to check for signs of inflammation, monitor conditions like rheumatoid arthritis, heart disease, or infections, or evaluate responses to treatments. High-sensitivity CRP is often used to assess low-level inflammation that standard CRP might miss.

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 provider know before the test.

What the Results Mean

Results are not provided as a single numeric range since reference intervals vary by lab. Elevated levels may indicate inflammation, infection, or autoimmune conditions, while normal levels suggest no significant inflammation. Your provider will interpret results in the context of your health.

Common Conditions Monitored

This test is commonly used to monitor conditions like cardiovascular disease, inflammatory bowel disease, and certain infections. It may also help guide treatment decisions for chronic conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CRP is a marker of systemic inflammation. While it doesn’t diagnose specific conditions, it helps identify areas where inflammation may be affecting your body. High CRP levels can signal an ongoing immune response, which may require further evaluation or treatment adjustments.

Short name

CRP (High-Sensitivity)

Frequently asked questions

What causes CRP levels to be high?
CRP levels can rise due to infections (like pneumonia or urinary tract infections), injuries, surgeries, or certain medical conditions such as autoimmune diseases (e.g., lupus) or heart disease. Stress, obesity, or smoking may also contribute to elevated CRP.
How often should I get this test?
Your healthcare provider will determine the frequency based on your medical needs. Some people get it annually for general health checks, while others may need it more often if they have ongoing conditions like heart disease or arthritis.
Does diet or exercise affect CRP levels?
Yes, lifestyle factors like diet (e.g., Mediterranean diet), regular exercise, and weight management can influence CRP levels. Reducing inflammation through these changes may lower CRP, but results depend on individual health and habits.
  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