Strokes can be classified into two main categories:
Hemorrhagic strokes occur when a blood vessel that supplies the brain ruptures and bleeds. When an artery bleeds into the brain, brain cells and tissues do not receive oxygen and nutrients. In addition, pressure builds up in surrounding tissues and irritation and swelling occur. About 13 percent of strokes are caused by hemorrhage (10 percent are intracerebral hemorrhage and 3 percent are subarachnoid hemorrhage strokes).