What is a Stroke?
A stroke occurs when the blood supply to the brain is interrupted, depriving part of the brain of oxygen and causing brain cells to die.
There are two types of stroke: hemorrhagic and ischemic. Both exhibit the same stroke symptoms.
The most common type of stroke occurs when blood flow to the brain’s cells is blocked, typically by a clot or piece of plaque getting wedged inside a blood vessel. Ischemic strokes account for 85 percent of all strokes.
Transient Ischemic Attack (TIA), also known as a “mini stroke,” is caused by a blockage of blood flow to a tiny artery, which causes stroke symptoms that almost always resolve within an hour. Even though the symptoms go away, anyone experiencing this should call 911 immediately to be evaluated and closely monitored. Fifteen percent of people who experience a TIA suffer an ischemic stroke a short time later, usually within a few days.
A hemorrhagic stroke occurs when a blood vessel breaks, causing blood to seep into brain tissue. Hemorrhagic strokes account for only 15 percent of all strokes, but are responsible for more than 30 percent of stroke deaths. The symptoms are the same as they are for ischemic stroke, with an added possible symptom of severe headache.
- An intracerebral hemorrhage occurs when a blood vessel within the brain tissue ruptures.
- A subarachnoid hemorrhage occurs when a weakened area of a blood vessel, called an aneurysm, breaks and blood is spilled around the surface of the brain.