Hypertension…. The pressure of blood against the walls of arteries is recorded as two numbers….the systolic pressure (as the heart beats) over….. the diastolic pressure (as the heart relaxes between beats). Normal blood pressure is less than 120 milliliters of mercury systolic and less than 80 milliliters mercury diastolic.
Nearly 50 million Americans have high blood pressure. If left untreated, high blood pressure can lead to strokes, heart attacks, and kidney failure. Conversely, controlling elevated blood pressure can cut strokes 35 to 40 percent and heart attacks 20 to 25 percent. Often, dietary and other lifestyle changes are sufficient to keep blood pressure controlled. If not, it may be necessary to add blood pressure medications such as diuretics, ACE inhibitors, beta blockers, or calcium channel blockers.
(Source: NYT Guide to Essential Knowledge )