Symptoms and signs

Strokes can be categorized into two main classifications: ischemic and hemorrhagic. The ischemic are due to obstruction of the blood supply, while the hemorrhagic are the due to rupture of blood vessels or some abnormal vascular structure. 4/5 of strokes are due to ischemia; the others are due to hemorrhage. Some hemorrhages develop inside a ischemia, which is called hemorrhagic transformation. It is unclear that how many hemorrhages start off as ischemic strokes.