Hypertension is common in the adult population of the United States. It has been demonstrated to be associated with increased cardiovascular morbidity and mortality. Alcohol consumption is also prevalent and may play an important causative or contributory role to elevate blood pressure in up to one-third of all hypertensives. The association between hypertension and alcohol consumption awaits causative explanation. Elucidation of the pathophysiology of the alcohol associated increment in blood pressure is the purpose of this study. Blood pressure is measured using a 24-hour ambulatory monitoring system for several days in normotensive and hypertensive social drinkers during periods of usual alcohol consumption and abstinence. Subjects are on a low monoamine diet for the duration of the study. Blood and urine samples are obtained during baseline or usual alcohol consumption, abstinence, and return to baseline levels of alcohol intake for measurement of neurotransmitters, neuromodulators, and electrolytes involved in blood pressure regulation. Changes in these regulatory systems are related to blood pressure in the three phases of the study.