A stroke is caused when blood flow in the brain is blocked,
depriving the brain of oxygen and causing the death of cells. Blood flow is
disrupted in two ways.
Clot
In an ischemic stroke, a blood clot
slows or stops blood flow to the brain. A clot can originate in the brain, or
it can travel from another part of the body, such as from the heart. Clots are
responsible for about 90 percent of all strokes.
Blood clots can be formed by
atherosclerosis, a condition where the walls of arteries become hardened and
