What happens during a stroke?
There are two basic types of stroke: hemorrhagic (having to do with an increase of blood to the brain) and ischemic (having to do with a decrease in the blood supply to the brain).
A hemorrhagic stroke occurs when a weakened artery leaks blood into the brain. High blood pressure batters at the artery until it bursts. When blood flows into the brain, it causes extensive damage.
There are two types of ischemic strokes: thrombotic and embolic. Thrombotic strokes occur when calcium buildups and fatty deposits (commonly known as plaque) build up on the inside walls of an artery supplying blood to the brain. The plaque eventually clogs the artery, and cuts off the brain’s blood supply. The build-up of plaque is a condition known as intracranial atherosclerosis.
An embolic stroke takes its name from embolus, another word for a blood clot. This type of clot breaks off from another part of the body, travels through the bloodstream, and gets stuck in a blood vessel leading toward the brain, blocking blood flow.
Are there any other types of stroke I should know about?
Yes. Many people suffer from strokes known as TIAs or RINDs.
TIA stands for "transient ischemic attacks." You may have heard these attacks referred to as pencil strokes. Their symptoms – including weakness or numbness of the face; weakness or numbness in one or both limbs on one side; difficulty in speaking, understanding speech, and reading; and vision disturbances – often mimic those of a full-blown stroke.
The main difference between a TIA and a full-blown stroke is that TIA symptoms last for less than twenty-four hours. Nevertheless, a TIA is serious because it is a temporary interruption of the blood supply to the brain. About a third of patients suffering from a transient ischemic attack will eventually have a full-blown stroke.
A RIND is a "reversible ischemic neurological deficit." Unlike a pencil stroke, a RIND lasts for more than twenty-four hours, but for less than three weeks.