Mild hypertension: to treat or not to treat?

Clinical practice must be based on the results of clinical trials, not on theories derived from epidemiology observations. The major trials of blood pressure reduction are described, and some of their shortcomings are discussed. Whenever drug treatment is necessary there will inevitably be a balance between benefits of treatment and unwanted effects of medication. The MRC trial of treatment in mild hypertension demonstrated that a small reduction in the risk of stroke is obtained at the cost of a variety of side effects which themselves depend on the medication used. Treatment of a diastolic pressure of 100 mm Hg or below will confer very little benefit on an individual patient.