The nature of essential hypertension as a mass public health problem throughout the United States, and internationally as well, is recognized generally. Prevalence estimates exceed l5 percent in most adult populations. Further, the results of the Hypertension Detection and Follow-up Program (HDFP) demonstrated the efficacy of antihypertensive therapy even at the 90-l05 mmHg level, which comprises 72 percent of the total hypertensive population. The Joint National Committee on the Detection, Evaluation and Treatment of High Blood Pressure recommended treatment of mild hypertension by pharmacologic or non-pharmacologic therapy to the lowest diastolic pressure consistent with safety and tolerance. The recommendation was consonant with the goal blood pressure guidelines for those with baseline pressures from 90-99 mmHg. Hence, there appeared to be a growing consensus that reduction of blood pressure to levels as low as 80 mmHg might be desirable for optimal cardiovascular health. The Joint National Committee further recommended that, in young patients with uncomplicated mild hypertension, the benefits from pharmacologic therapy must be weighed against the cost, inconvenience, and possible side effects. There was, therefore, a growing concern over the need for pharmacologic management of hypertension and the public health implications of such a course of action. These recommendations toward intervention in mild hypertension set a firm basis for the primary prevention of hypertension.