Hypertension means excessively high tension. Though normal blood pressure varies from person to person, it should be respectively maximum 130 mm Hg for systolic and maximum 85 mm Hg for diastolic.
Generally accepted blood pressure in a normal adult at rest is 120/80 mmHg (millimeter mercury).
If the arterial pressure in carriage of blood from heart to tissues is constantly above 140/90 mmHg, it is termed as hypertension.
Hypertension is a main risk factor for cardiac diseases. If not treated, it causes an increase in such severe diseases as brain, cardiovascular and renal diseases and in fatality. Once it is diagnosed and started to be treated, the high tension may be reduced, and the risk of cardiovascular system diseases may be diminished.