Abstract
Observational epidemiological studies demonstrate a direct continuous relationship between the level of usual blood pressure and the incidence of stroke. The level of blood pressure appears to be an important determinant of stroke risk in normotensives as well as hypertensives. Clinical trials of blood pressure reduction in hypertensive patients suggest that much or all of the stroke avoidance associated with prolonged blood pressure differences are achieved within a few years of beginning treatment. In this regard, the effects of diuretics and beta-blockers have not been shown to be clearly different. Two important areas for future research in the prevention of stroke concern the effects of blood pressure reduction in high risk normotensive individuals (e.g. those with a history of transient cerebral ischaemia) and the effects of antiplatelet therapy in hypertensive individuals.