Hypertension is the increase in blood pressure values, measured at rest, over 160 mmHg for systolic (maximum) pressure and / or 95 mmHg for diastolic (minimum) pressure.
These threshold values of arterial pressure have been set by the World Health Organization and must be considered conventional, since there are no precise values in which one abruptly enters the pathological field.
Hypertension is an extremely frequent disease that affects about 20% of the European and North American adult population. There is a slight prevalence of male sex in the younger age, a trend that is reversed in later ages as the frequency increases strongly in female sex after menopause.
Hypertension appears to be related to economic development; in fact, it does not exist in the populations of the developing countries and in these same populations the blood pressure does not tend to increase with age, indeed very often it tends to decrease in old age.
Other factors related to hypertension are obesity, stress, smoking, physical inactivity, and abuse in eating salt.
There is a significant correlation between the levels of blood pressure in a population and its overall mortality.