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C-reactive protein (CRP) – Serum/Plasma Concentration (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, often used to assess low-grade inflammation or risk for conditions like heart disease.

Quick summary

["High-sensitivity CRP helps track subtle inflammation that may not show up on other tests."]

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

Key facts at a glance

LOINC
50378-9
Short code
vWF CBA/vWF Ag PPP IA-Rto
Synonyms
vWF CBA/vWF Ag PPP IA-Rto
Category
chemistry
Sample
plasma
Container
Lavender-top (EDTA) or Green-top (Heparin)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
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 It’s Done

Your doctor may order this test to monitor chronic inflammation, evaluate risk for cardiovascular events, or check for conditions like rheumatoid arthritis, lupus, or other inflammatory diseases. It’s sometimes used alongside other tests to guide treatment decisions.

What to Expect

A small blood sample is drawn from a vein, usually in your arm. You may feel a slight pinch, but it’s over quickly. No special preparation is needed, though you might be asked to avoid strenuous activity for a few hours before the test.

How It Works

The test detects the presence and amount of CRP, a protein produced by the liver in response to inflammation. High levels may indicate an ongoing inflammatory process, while normal levels suggest low or no inflammation.

What the Results Mean

Results are reported in milligrams per liter (mg/L). While reference ranges vary by lab, higher-than-normal levels may signal inflammation, infection, or other health concerns. Your doctor will interpret results in the context of your overall health and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

High-Sensitivity CRP (hs-CRP)

Frequently asked questions

What does a high CRP level mean?
A high CRP level often points to inflammation, which can be linked to conditions like heart disease, autoimmune disorders, or infections. It’s not a definitive diagnosis but may prompt further testing or adjustments to treatment plans.
How often should I get this test?
Your doctor will determine the frequency based on your health needs. Some patients get it yearly to monitor long-term inflammation, while others may need it more often if they have ongoing health concerns.
Can lifestyle changes affect CRP levels?
Yes! Diet, exercise, and stress management can influence CRP levels. Reducing inflammation through healthy habits may lower CRP, but results depend on individual factors and should be discussed with your healthcare provider.
  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