This is a little question without a simple answer. With stroke being down over all but up in the age group of 18-54, causes of stroke vary greatly. We know that strokes can happen when the blood supply to the brain is reduced (Ischemic Stroke) or interrupted (Hemorrhagic Stroke). This deprives the brain of oxygen and nutrients leaving brain cells dead, within minutes. Some people have what is called a TIA/ Transient Ischemic Attack, or mini stroke, which tends to be a very short temporary blockage that resolves itself and doesn't leave permanent brain damage. TIA's can be a precursor to a full on brain attack and should be treated seriously. BUT why does this happen is the BIG question.
Here are some reason known to cause stroke. It is not as if these are steadfast, sure-fire reasons for a stroke, but they can increase a person's likelihood. Keep in mind, some of these issues can be changed and some may not.
Now that you have a clearer picture of the causes of stroke, come back next time as I teach how to recognize a stroke.