About two-thirds of people who suffer a first stroke have moderate elevated blood pressure (160/95 mm Hg or above). Hypertensive people have up to 10 times the normal risk of stroke, depending on the severity of the blood pressure in the presence of other risk factors. Hypertension is also an important cause of silent cerebral infarcts, which are blockages in the blood vessels in the brain (mini-strokes) that may predict major stroke or progress to dementia over time.