OPTIMAL BLOOD PRESSURE REDUCTION: The optimal blood pressure reduction when treating arterial hypertension is obviously the one which causes the maximum achievable prevention of hypertension-associated cardiovascular morbidity and mortality. This goal has not yet been reached by present approaches to antihypertensive treatment. Several large intervention trials in hypertension have shown that treated hypertensive patients still have an increased risk of cardiovascular morbidity and mortality in spite of receiving antihypertensive treatment. One possible explanation for this is that treated blood pressure is rarely, if ever, reduced to strictly normotensive levels. Another explanation, favored by proponents of the J-curve argument, is that excessive lowering of blood pressure may increase cardiovascular risks. DATA AVAILABLE FROM INTERVENTION TRIALS: So far, two prospective intervention trials have addressed this problem, the Swedish BBB (Treat Blood Pressure Better) study, for which results have been published, and the much larger Hypertension Optimal Treatment (HOT) study, which is still under way. Moreover, new epidemiological data from the Framingham Heart Study and the study of 50-year-old men in Gothenburg suggest that active intervention against arterial hypertension may change the pattern of blood pressure distribution in the population towards lower levels, also in untreated subjects, suggesting an additional and unexpected benefit from antihypertensive treatment.