Response to placebo treatment in hypertension

In essential hypertension, the blood pressure is variable, with large changes occurring in response to variations in physical and emotional stimuli. Patients given placebo tablets often have short-lived decreases in blood pressure. Placebo-controlled studies are essential for the proper evaluation of antihypertensive drugs. In longer term studies in mild hypertension, many patients given placebos have substantial decreases in blood pressure, often to normal levels, a finding that makes a period of observation desirable before commencing active treatment. Patients given placebos also have a high incidence of symptomatic side effects.