The 1997 recommendations for diagnosing, evaluating, and treating mild to moderate hypertension, made in the Sixth Report of the Joint National Committee on Prevention, Detection and Treatment of High Blood Pressure, are reviewed in this article. Because drug therapy may actually increase the risk of morbidity and mortality for hypertensive patients at low risk for adverse cardiovascular outcomes, not all patients with borderline hypertension should be treated with pharmacotherapy. Treatment decisions should be based not only on blood pressure level but also on the presence of additional risk factors, the existence of clinical cardiovascular disease, and evidence of target ogan damage. The reviewed national guidelines recommend a risk stratification approach to determining the appropriate therapy level for patients with hypertension. The newest hypertension classifications and recommendations for risk assessment, patient classification, the appropriate initial level of therapy, and follow-up are presented.