Results from a large number of randomized clinical trials document conclusively that treatment of elevated systolic and/or diastolic blood pressure markedly reduces the risk of cardiovascular complications such as stroke and acute myocardial infarction. Detection, treatment and control of hypertension have major public health implications. A review of the literature suggests the existence of both overtreatment (defined as improper or incorrect diagnosis of hypertension, overaggressive and potentially dangerous blood pressure lowering and the use of expensive antihypertensive drugs with unproven mortality/morbidity benefits) and undertreatment (defined as unrecognized, untreated and poorly controlled hypertension). These current major issues in medicine are discussed.