Cardiovascular disease continues to be the principal cause of death in Western countries. Epidemiological studies have repeatedly demonstrated a striking relationship between blood pressure and the risk of cardiovascular disease in that those with the highest levels of blood pressure are at the greatest risk for subsequent disease or death. However, most blood pressure-related cardiovascular complications occur at much lower levels of blood pressure. Any attempt to substantially reduce the frequency of blood pressure-related cardiovascular disease mandates treatment of large numbers of asymptomatic subjects who are, on average, only exposed to a slight increase in risk. Based on current demographic trends, this requirement will become even more striking in the future. Non-pharmacological interventions provide the most attractive approach to the prevention and treatment of high blood pressure. However, the efficacy and acceptability of long term non-drug treatment is uncertain. Drug treatment remains the best proven and fundamental approach to the treatment of established hypertension. Based on the lifelong nature of antihypertensive therapy and the changing risk profile of those being treated, a desire to recognise and prevent adverse effects of antihypertensive drug administration is now more important than ever. Special care is essential during the treatment of uncomplicated mild hypertensives with few or no other cardiovascular risk factors.