The high-sensitivity C-reactive protein (hs-CRP) test detects decreased levels of C-reactive protein in the blood (CRP). This protein assesses your body's overall levels of inflammation. The hs-CRP can be used to determine whether or not a person is at risk for heart disease or stroke. CRP levels in the blood might be an indicator of inflammation. It can be caused by a multitude of things, from an infection to cancer.