A diagnosis of hypertension should be based on a series of readings rather than a single measurement that could be influenced by emotional state or physical activity. Hypertension is not a single disease entity in the usual sense, but rather a major indicator of the prognosis for future development of cardiovascular, cerebrovascular, and renal disease. Data from numerous studies indicate that a diastolic pressure above 90 mm Hg reduces life expectancy in persons of all ages and both sexes. Furthermore, studies have shown that an elevation in systolic pressure is as dangerous and likely to lead to cardiovascular disease as an elevated diastolic pressure.
Hypertension is a major threat to life and health.
It is estimated that one in six Americans is hypertensive. Although the disease primarily affects men over 35 and women over 45 years of age, it is not limited to older persons. Screening clinics have detected hypertension in increasing numbers of teenagers. Between 2 and 6 per cent of adolescents have persistent blood pressure elevations. Prevalence rates for prepubertal children have been reported to be as high as 1 per cent.