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C-reactive protein (high-sensitivity) concentration

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

This test measures a protein in your blood that rises when inflammation is present, often used to assess low-grade inflammation or risk for future health issues.

Quick summary

["hs-CRP helps track inflammation that may not be obvious from other symptoms."]

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

Key facts at a glance

LOINC
7184-5
Short code
CATDG
Synonyms
Cat Dander IgG Qn
Category
chemistry
Sample
serum
Container
Serum separator tube (SST) or red-top tube
Units
N/A
Ref low
0.35
Ref high
0.7
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
Enzyme Immunoassay (EIA) or ImmunoCAP
CPT
86001
Specimen volume
1 mL serum
Stability
Room temperature: 8 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
24–72 hours
Order
routine

What Is hs-CRP Used For?

Doctors may order hs-CRP to monitor chronic inflammation, evaluate cardiovascular risk, or check for conditions like arthritis or infections. It’s sometimes used alongside other tests to guide treatment decisions.

How Is the Test Done?

A small blood sample is taken from your arm. The test measures the protein level in your serum or plasma using a sensitive immunoassay method.

Why Might You Need This Test?

You might need hs-CRP if you have symptoms of inflammation, a history of heart disease, or if your doctor wants to assess your long-term health risks.

What Does a High or Low Result Mean?

Results can vary based on your health status. A higher-than-normal level may suggest inflammation or increased risk of conditions like heart disease, while lower levels may indicate less inflammation.

Reference range

Negative: <0.35 U/mL; Equivocal: 0.35-0.70 U/mL; Positive: >0.70 U/mL (laboratory-specific reference ranges may vary)N/A

Specimen: serum

No special preparation required. Patient may be advised to discontinue antihistamines or corticosteroids prior to testing if clinically appropriate, but this does not affect IgG antibody levels.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

hs-CRP is a marker for systemic inflammation, often used to assess cardiovascular risk or monitor chronic conditions like rheumatoid arthritis. It’s not diagnostic on its own but can help guide treatment plans.

Short name

hs-CRP

Frequently asked questions

Why do I need this test if I don’t have symptoms?
Even without obvious symptoms, inflammation can be present. hs-CRP helps doctors check for hidden risks, especially in people with a family history of heart disease or other inflammatory conditions.
Can lifestyle changes affect hs-CRP levels?
Yes! Diet, exercise, and managing stress can lower inflammation. Small changes, like eating heart-healthy foods or quitting smoking, may help reduce hs-CRP levels over time.
How often should I get this test?
Your doctor will determine how often you need it based on your health needs. It’s often checked periodically for people at higher risk for heart disease or chronic 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