It s the silent killer, there are really no visual signs. Health Tip: High Blood Pressure, a Silent Killer (HealthDay News) -- Blood pressure is the pressure of blood applied to the walls of the arteries when the heart beats (the top number -- called systolic pressure), and when it s at rest (diastolic pressure). Normal blood pressure for adults is considered less than 120 over 80, the American Heart Association says. Often there are no signs or symptoms of high blood pressure. Yet it directly raises a person s risks of heart attack and stroke. It s best to have your blood pressure checked at least once every two years, the association says. If you have high blood pressure, also called hypertension, your doctor may recommend changes in diet, getting more exercise, quitting smoking, and in some cases, medication. -- Deborah DiSesa Hirsch