Inflammation is the process that helps the body to fight infection or injury. A growing amount of information suggests that inflammation plays a role in the development of blockages in blood vessels and, thus, helps to cause cardiovascular events, such as heart attack or stroke. For example, the blood levels of certain substances caused by inflammation are higher in people who develop cardiovascular disease than in people who do not. C-reactive protein (CRP) is one such inflammatory substance. However, CRP levels in the blood are increased in several types of illness and therefore may just be a marker of various illnesses rather than a reliable sign of cardiovascular disease.