A stroke occurs when a blood flow to an area of the brain is interrupted by a blood vessel breaking (hemorrhage) or a blood clot blocking an artery. This is called an ischemic stroke. When either a hemorrhage or blood clot in the brain occurs, brain cells begin to die, and brain damage can result.
When brain cells die, the physical abilities controlled by that area of the brain become impaired. These can include speech, memory and movement. The abilities affected by stroke depend on where in the brain the stroke occurs and how much damage is done.
Strokes caused by hemorrhage, called hemorrhagic strokes, account for only 20 percent of strokes overall.