Other Risk Factors
The most important risk factors for Stroke are hypertension, heart disease, Diabetes, and cigarette smoking. Others include heavy alcohol consumption, high blood Cholesterol levels, illicit drug use, and Genetic or congenital conditions, particularly vascular abnormalities. People with more than one risk factor have what is called "amplification of risk." This means that the multiple risk factors compound their destructive effects and create an overall risk greater than the simple cumulative effect of the individual risk factors.

Hypertension
Of all the risk factors that contribute to stroke, the most powerful is hypertension, or high blood pressure. People with hypertension have a risk for stroke that is four to six times higher than the risk for those without hypertension. One-third of the adult U.S. population, about 50 million people (including 40-70 percent of those over age 65) have high blood pressure. Forty to 90 percent of stroke patients have high blood pressure before their stroke event.

A systolic pressure of 120 mm of Hg over a diastolic pressure of 80 mm of Hg is generally considered normal. Persistently high blood pressure greater than 140 over 90 leads to the diagnosis of the disease called hypertension. The impact of hypertension on the total risk for stroke decreases with increasing age, therefore factors other than hypertension play a greater role in the overall stroke risk in elderly adults. For people without hypertension, the absolute risk of stroke increases over time until around the age of 90, when the absolute risk becomes the same as that for people with hypertension.

Like stroke, there is a gender difference in the prevalence of hypertension. In younger people, hypertension is more common among men than among women. With increasing age, however, more women than men have hypertension. This hypertension gender-age difference probably has an impact on the incidence and prevalence of stroke in these populations.

Antihypertensive medication can decrease a person's risk for stroke. Recent studies suggest that treatment can decrease the stroke incidence rate by 38 percent and decrease the stroke fatality rate by 40 percent. Common hypertensive agents include adrenergic agents, beta-blockers, angiotensin converting enzyme inhibitors, calcium channel blockers, diuretics, and vasodilators.