Stroke Overview See All  Types of Stroke in Stroke Overview Strokes are classified as either ischemic or hemorrhagic. Ischemic strokes are caused by the blockage of an artery. Hemorrhagic strokes are caused by bleeding in the brain. ...more  Stroke in Stroke Overview A stroke, or brain attack, happens when blood flow to your brain is stopped. It is an emergency situation. ...more  Subarachnoid Hemorrhage in Stroke Overview A subarachnoid hemorrhage means that there is bleeding in the space that surrounds the brain.