What is High-Sensitivity C-Reactive Protein (hs-CRP)?
hs-CRP is a blood test that measures very low levels of C-reactive protein, a protein your liver makes when there is inflammation in your body, and it helps predict your risk of having a heart attack or stroke in the future. 1
Understanding the Test
- hs-CRP measures inflammation in your blood vessels that can lead to heart disease, even when you feel completely healthy and have no symptoms 1
- The test requires a single blood sample and is widely available at most laboratories 1
- It uses a more sensitive measurement technique than regular CRP tests, allowing detection of very small amounts of inflammation that matter for heart health 2
What the Numbers Mean
Your doctor will interpret your results using three risk categories: 3, 2
- Less than 1 mg/L = Lower cardiovascular risk
- 1 to 3 mg/L = Average/moderate cardiovascular risk
- Greater than 3 mg/L = Higher cardiovascular risk
These levels indicate approximately a 2-fold increased relative risk when comparing high-risk to low-risk categories 3
Why Your Doctor Ordered This Test
- hs-CRP is most useful when your 10-year heart disease risk falls in the intermediate range (10-20%), meaning your doctor needs additional information to decide whether you should start medications like statins or aspirin 1
- The test adds prognostic information comparable to blood pressure or cholesterol measurements 4
- It helps identify inflammation that traditional risk factors like cholesterol, blood pressure, diabetes, and smoking history might miss 1
Important Things to Know
- If your level is above 10 mg/L, your doctor will retest you in 2 weeks to check for other causes of inflammation like infections, arthritis, or other medical conditions unrelated to your heart 1, 3
- The test has natural variability, so your doctor typically orders two separate measurements to accurately classify your risk level 1
- This test does NOT diagnose a heart attack—it predicts future risk in people who currently feel well 1
What Affects Your hs-CRP Levels
Factors that increase your levels include: 1
- High blood pressure
- Being overweight
- Cigarette smoking
- Diabetes
- Low HDL ("good") cholesterol and high triglycerides
- Chronic infections like gum disease
Factors that decrease your levels include: 1
- Moderate alcohol consumption
- Regular exercise
- Weight loss
- Certain medications (statins, fibrates, niacin)
What Happens Next
- Your doctor will use this result along with your other risk factors—not by itself—to make decisions about prevention strategies 1
- If elevated, first-line approaches include diet modification, exercise, weight loss, and smoking cessation 1
- For patients with intermediate risk and elevated hs-CRP, statin therapy may reduce your risk of heart attack and stroke by approximately 47% 4
- Your doctor should NOT reorder this test repeatedly to monitor treatment, as serial testing is not recommended 1, 3
Key Takeaway
Think of hs-CRP as an "inflammation thermometer" for your blood vessels—it helps your doctor see hidden inflammation that increases your heart disease risk, allowing for earlier and more targeted prevention strategies before problems occur 2, 5