| • | Stroke Overview A stroke is an illness that suddenly disrupts the brain's function by interfering with part of its blood supply. |
| • | Hemorrhagic Stroke A hemorrhagic stroke is bleeding (hemorrhage) that suddenly interferes with the brain's function by cutting off part of its blood supply. |
| • | Lacunar Stroke A lacunar stroke is a blockage of blood flow to a part of the brain supplied by one of the brain's smaller penetrating arteries. |
| • | Subarachnoid Hemorrhage A subarachnoid hemorrhage is a type of stroke in which bleeding from a damaged blood vessel causes an accumulation of blood at the surface of the brain. |
| • | Thrombotic Stroke In a thrombotic stroke, a blood clot (thrombus) forms inside one of the brain's arteries and blocks blood flow to a part of the brain. |
| • | Transient Ischemic Attack (TIA) A transient ischemic attack (TIA) is an episode of strokelike symptoms that lasts less than 24 hours (usually 5 to 20 minutes). |