A "blockage stroke," also called an Ischemic stroke, occurs when a blood clot forms within the brain vessel wall or somewhere else in the body (usually from the heart) and travels through the bloodstream to the brain. Once in the brain, the clot travels until it enters a vessel small enough to block its passage. The clot lodges in the blood vessel, blocking the flow of blood to a part of the brain. When the brain tissue is deprived of blood, it begins to die very rapidly. Blockage strokes can also occur due to a buildup of fatty deposits and cholesterol. Your body interprets this buildup within the vessels of your brain as an injury therefore it responds by forming clots.