A stroke is commonly caused by a blocked artery (a blood vessel which carries blood from the heart) or the leak or burst of a blood vessel. Most strokes are classified as ischemic strokes. In an ischemic stroke, an artery to the brain becomes blocked or reduced. The cause of the blockage is usually a blood clot or plaque (a buildup in the walls of arteries). Strokes may also be classified as hemorrhagic strokes or transient ischemic attacks (TSA). In an ischemic stroke, a blood vessel in the brain ruptures or leaks. In a TSA, sometimes called a “mini-stroke,” symptoms of a stroke are present but these last less than five minutes and may not have longterm effects.