A stroke is a "brain attack". It happen when the blood supply to part of your brain is interrupted or reduced, depriving brain tissue of oxygen and nutrients. Within minutes, brain cells begin to die. When brain cells die during a stroke, abilities controlled by that area of the brain such as memory and muscle control are lost. There are two kinds of stroke. First one called as ischemic stroke, is caused by a blood clot that blocks or plugs a blood vessel in the brain. The other one, called hemorrhagic stroke, is caused by a blood vessel that breaks and bleeds into the brain.