C-reactive protein (CRP) is known to increase when there is inflammation in the body. Inflammation has been linked with atherosclerosis by various different clinical research studies. Therefore, it has been suggested that testing for CRP levels in the blood can help detect an individual’s risk of getting a heart disease. However, there are two types of tests that can detect CRP levels in blood- (1) one that detects high levels of CRP and (2) the other is a highly sensitive assay that detects very low levels of CRP (hs-CRP). Higher levels of CRP could be seen in case of systemic inflammation, whereas very low increase in CRP level is observed in case of vascular inflammation, which has been linked with atherosclerosis, which means formation of fatty deposits or plaques in the inner lining of arterial walls. High levels of hs-CRP may also be helpful in determining the overall risk of stroke or peripheral artery disease. Several different studies have shown that higher levels of hs-CRP mean higher risk of heart attack. Some of the major factors that can contribute to vascular inflammation include- smoking, hypertension, hyperglycemia and/or dyslipidemia. People who do not exercise and have sedentary lifestyles may also have higher CRP levels. Patients with any of these conditions and/or who are centrally obese should be tested for hs-CRP levels; and if the levels are higher than 3.0 mg/dL, then they should be retested to confirm high levels. The CRP levels higher than 10.0 mg/dL could indicate non-cardiovascular causes of inflammation and those could include infectious diseases, some autoimmune disorders or even cancer.