Prospective observational studies show clearly that the risks of stroke, coronary heart disease and premature death are related directly to BP. Furthermore, the results of prospective, randomised intervention studies indicate that effective BP control reduces these risks. Although the number of patients being treated for hypertension has approximately doubled in the last 20 years, premature morbidity and mortality remain higher than in the normotensive population, This may relate to the inadequate level of BP control achieved in many patients. Two large studies have shown that DBP can be reduced to < 90 mmHg in almost all patients if antihypertensive therapy is intensified, and preliminary evidence suggests that this can be done without increasing the incidence of side-effects. The level to which BP should be reduced to achieve an optimum reduction in cardiovascular morbidity and mortality is currently being investigated in the Hypertension Optimal Treatment (HOT) Study.