Blood supply to the brain can be interrupted in two ways – 1.) Blood clot forms (ischemic stroke) and 2.) A blood vessel ruptures causing blood to leak into the brain (hemorrhagic stroke).
Ischemic Stroke & Hemorrhagic Strokes
Ischemic strokes (caused by a blood clot in the brain) account for about 83 percent of all stroke cases.
Hemorrhagic strokes (ruptured blood vessel in the brain) account for about 17 percent of all stroke cases, and it results from a weakened vessel that ruptures and bleeds into the surrounding brain.
Transient Ischemic Attacks
Also called TIAs, transient ischemic attacks are minor or temporary strokes. In a TIA, conditions indicative of an ischemic stroke are present and the typical stroke warning signs develop. However, the obstruction (blood clot) occurs for a short time and tends to resolve itself through normal mechanisms.
Even though the symptoms disappear after a short time, TIAs are strong indicators of a possible major stroke so get to the hospital immediately!
Source: American Heart Association