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C-reactive protein (CRP) by immunoassay (high-sensitivity)

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

This test measures a protein in your blood that rises when your body is fighting inflammation or infection.

Quick summary

["Helps track inflammation, infection risk, or response to treatment."]

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

Key facts at a glance

LOINC
21190-4
Short code
C trach DNA Cvx Ql NAA+probe
Synonyms
C trach DNA Cvx Ql 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 This Test Is Done

Doctors may order a high-sensitivity CRP (hs-CRP) test to monitor chronic conditions like heart disease, arthritis, or inflammation. It can also help assess risk for conditions like heart attacks or infections before symptoms appear.

What to Expect Before the Test

No special preparation is needed. You’ll provide a small blood sample, usually drawn from your arm. If you’re on blood thinners, let your doctor know before the test.

What the Results Mean

Results are used to compare against general reference ranges for inflammation. Higher levels may indicate ongoing inflammation, infection, or other health concerns.

Common Conditions Monitored

Hs-CRP is often used to evaluate conditions like cardiovascular disease, autoimmune disorders, or post-surgery healing. It’s not a diagnostic test alone but supports overall health assessment.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical significance: Elevated hs-CRP suggests increased inflammation, which may signal underlying conditions like cardiovascular risk, infections, or autoimmune activity. Lower levels may indicate reduced inflammation. Results are interpreted in context with patient history and other tests.

Short name

hs-CRP

Frequently asked questions

What does a high hs-CRP level mean?
A high hs-CRP level may signal inflammation or infection, but it doesn’t diagnose a specific condition. Your doctor will consider your symptoms, medical history, and other tests to determine next steps.
Can diet or exercise affect hs-CRP levels?
Yes, lifestyle factors like diet, exercise, and smoking can influence inflammation. Reducing processed foods, increasing omega-3s, and staying active may help lower levels over time.
Is hs-CRP the same as a general CRP test?
Yes, hs-CRP is a high-sensitivity version of CRP that detects smaller amounts of the protein, making it more precise for detecting mild 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