Stroke occurs when the supply of blood to the brain is either interrupted or reduced. When this happens, the brain does not get enough oxygen or nutrients which causes brain cells to die.
Strokes occur due to problems with the blood supply to the brain; either the blood supply is blocked or a blood vessel within the brain ruptures.
There are three main kinds of stroke; ischemic, hemorrhagic and TIA. This article will focus on ischemic and hemorrhagic strokes, as there is a separate Knowledge Center article for TIAs, which goes into specific detail about them.
In the US, approximately 40% of stroke deaths are in males, with 60% in females. According to the American Heart Association (AHA), compared to white people, black people have nearly twice the risk of a first-ever stroke and a much higher death rate from stroke.3
In 2009, stroke was listed as the underlying cause of death in 128,842 persons in the US, resulting in an age-adjusted rate of 38.9 deaths per 100,000 population. The rate was almost twice as high among non-Hispanic blacks (73.6 per 100,000), and the rate of premature death from stroke was also higher among non-Hispanic blacks than their white counterparts (25.0 versus 10.2).17
Stroke is also more likely to affect people if they are overweight, aged 55 or older, have a personal or family history of stroke, do not exercise much, drink heavily, smoke or use illicit drugs.