The clinical and laboratory picture of hypertension is outlined. Diagnostic measurements are discussed. The treatment is discussed in details. It is classified in: a) non-pharmacologic approach: including measures, such as: weight reduction, alcohol restriction, sodium intake restriction, tobacco avoidance, biofeedback and relaxation, aerobic exercise program (walking, bicycling, jogging or swimming). b) pharmacologic therapy: points such as: when to initiate? how to treat and mainly why to treat hypertensive patients are discussed. Therapeutic classes are presented.