The Treatment of Hypertension With Drugs

THERE are times when the strident conflicts of investigators, the rise and fall of theories and the babel of unsorted evidence create such a sense of confusion in a field that an atmosphere of frustration and despair prevails in which no one believes anything; this has happened to some extent in hypertension.1 '- Yet somewhere between the extreme skepticism both of the very young and of the old and tired, and the transient enthusiasms of the protagonists of this theory or that remedy, lies a middle ground of achievement and even agreement. It is generally agreed, for example, that the cause of ordinary hypertension is narrowing of the terminal vascular bed of the systemic circulation, especially the arterioles.3'4 It is also gen-erally believed, although with some dissension, that there are three major causes of such narrowing.5'6'7 One is increased discharge via the sym-pathetic nervous system. Another is increased vasomotor tone produced either by circulating substances or by metabolic changes. A final cause is structural changes in the vessels themselves, frequently influenced at least in