It is estimated that the risk of stroke doubles for every decade after the age of fifty five. Nevertheless, stroke can be seen in young adults and even children, although the causes tend to be different than in the older age groups. Heredity plays a role in stroke, especially if one or more parents suffered a stroke. African-Americans have a higher risk of dying and being disabled by stroke than whites which probably, in large part, is related to a greater incidence of high blood pressure and diabetes. Diabetes mellitus is a clear risk factor for stroke, effecting both small and large blood vessels in the brain.
Cigarette smoking is likewise an important risk factor for stroke.
Someone who has had a prior stroke is at significant increased risk of having another stroke compared to individuals who have never had a stroke. High blood cholesterol and lipids can lead to both heart disease and stroke. Certain forms of heart disease can significantly increase the risk of having stroke. An individual who has an enlarged heart from what is known as a cardiomyopathy or prior heart wall damage from a heart attack, is at clearly increased risk of having a stroke. Individuals who have a cardiac arrhythmia, known as atrial fibrillation, can have an increased risk of stroke anywhere from five to seventeen times over the general population.