Target organ damage to the brain, heart or kidneys due to hypertension appears to differ in various ethnic groups. Prevention of such damage is by early recognition of mild hypertension and institution of treatment primarily by non-pharmacologic and if required drugs. Treatment of established damage is by both these methods. In the choice of drugs 24-hour control of blood pressure is essential as is regression of left ventricular hypertrophy. Other desirable qualities of the drugs are their anti-ischaemic and anti-atherogenic effects.