C-Reactive Protein (CRP)
Also known as: CRP, hs-CRP, High-Sensitivity CRP, Inflammation Marker
C-reactive protein (CRP) is a substance produced by the liver in response to inflammation. The CRP test measures the level of this protein in your blood. A high-sensitivity CRP (hs-CRP) test can detect lower levels and is used specifically to assess cardiovascular disease risk.
Purpose
Detecting and monitoring inflammation from infections, autoimmune diseases, or chronic conditions. Assessing cardiovascular disease risk (hs-CRP). Monitoring treatment effectiveness for inflammatory conditions (rheumatoid arthritis, lupus, inflammatory bowel disease). Detecting post-surgical infections. Differentiating between bacterial and viral infections.
Preparation
No fasting is typically required for standard CRP. For hs-CRP cardiovascular risk assessment, some providers prefer fasting. Acute infections, injuries, or recent exercise can temporarily elevate CRP — ideally test when you're feeling well. NSAIDs and statins can lower CRP levels.
Procedure
Standard blood draw from a vein in your arm. The blood sample is analyzed using immunoassay techniques. Takes about 5 minutes.
Normal Range
Standard CRP: Below 10 mg/L is normal. hs-CRP cardiovascular risk: Low risk: below 1.0 mg/L. Average risk: 1.0–3.0 mg/L. High risk: above 3.0 mg/L. Values above 10 mg/L suggest acute inflammation (infection, injury) rather than chronic cardiovascular risk and should be repeated when resolved.
Abnormal Results
Mildly elevated CRP (3–10 mg/L) may indicate low-grade chronic inflammation, obesity, smoking, or moderate cardiovascular risk. Moderately elevated CRP (10–100 mg/L) may suggest active infection, autoimmune flare, or significant inflammation. Highly elevated CRP (>100 mg/L) usually indicates severe bacterial infection, major trauma, or systemic vasculitis. Elevated hs-CRP is an independent risk factor for heart attack, stroke, and peripheral arterial disease.
Risks
Minimal — standard blood draw risks.
Turnaround Time
Results typically available within 24 hours.
Estimated Cost
$15–$80 without insurance. hs-CRP may be covered for cardiovascular risk assessment.
Frequently Asked Questions
What is a C-Reactive Protein (CRP) test?▼
C-reactive protein (CRP) is a substance produced by the liver in response to inflammation. The CRP test measures the level of this protein in your blood. A high-sensitivity CRP (hs-CRP) test can detect lower levels and is used specifically to assess cardiovascular disease risk.
What is the normal range for a C-Reactive Protein (CRP)?▼
Standard CRP: Below 10 mg/L is normal. hs-CRP cardiovascular risk: Low risk: below 1.0 mg/L. Average risk: 1.0–3.0 mg/L. High risk: above 3.0 mg/L. Values above 10 mg/L suggest acute inflammation (infection, injury) rather than chronic cardiovascular risk and should be repeated when resolved.
How do I prepare for a C-Reactive Protein (CRP)?▼
No fasting is typically required for standard CRP. For hs-CRP cardiovascular risk assessment, some providers prefer fasting. Acute infections, injuries, or recent exercise can temporarily elevate CRP — ideally test when you're feeling well. NSAIDs and statins can lower CRP levels.
What do abnormal C-Reactive Protein (CRP) results mean?▼
Mildly elevated CRP (3–10 mg/L) may indicate low-grade chronic inflammation, obesity, smoking, or moderate cardiovascular risk. Moderately elevated CRP (10–100 mg/L) may suggest active infection, autoimmune flare, or significant inflammation. Highly elevated CRP (>100 mg/L) usually indicates severe bacterial infection, major trauma, or systemic vasculitis. Elevated hs-CRP is an independent risk factor for heart attack, stroke, and peripheral arterial disease.
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Medical Disclaimer
This lab test information is for educational purposes only and should not replace professional medical advice. Lab results should always be interpreted by a qualified healthcare provider who knows your complete medical history. Normal ranges may vary between laboratories.