The Basics of a Stroke and High Blood Pressure A stroke, sometimes called a "brain attack," occurs when blood flow to an area in the brain is cut off. As a result, the brain cells, deprived of the oxygen and glucose needed to survive, die. If not caught early, permanent brain damage can result.

Uncontrolled high blood pressure increases a person's stroke risk by four to six times. Over time, hypertension leads to atherosclerosis and hardening of the large arteries. This, in turn, can lead to blockage of small blood vessels in the brain. High blood pressure can also lead to weakening of the blood vessels in the brain, causing them to balloon and burst. The risk of stroke is directly related to how high the blood pressure is.