C-Reactive Protein (CRP)
A C-reactive protein (CRP) test is a
blood test that measures the amount of a
protein called C-reactive protein in your
The normal values listed here—called a reference range—are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what's normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
Results are usually available within 24 hours.
Any condition that results in sudden or severe
inflammation may increase your CRP levels.
Some medicines may
decrease your CRP levels.
Many conditions can change CRP
levels. Your doctor will talk with you about any abnormal results that may be
related to your symptoms and past health.
High-sensitivity C-reactive protein (hs-CRP) levels
High-sensitivity C-reactive protein (hs-CRP) measures very low
amounts of CRP in the blood. This test may help find your risk of heart problems, especially when it is considered along with other risk factors such as cholesterol, age, blood pressure, and smoking. It may be done to
find out if you have an increased chance of having a sudden heart problem, such
heart attack or stroke. But the connection between high CRP
levels and heart disease risk is not understood very well.
High-sensitivity C-reactive protein (hs-CRP) level
Less than 0.1
mg/dL or less than 1 mg/L
hs-CRP level and heart disease risk
Less than 1.0 mg/L
1.0 to 3.0 mg/L
More than 3.0 mg/L
What Affects the Test
You may not be able to have the
test or the results may not be helpful if: