"Abnormal sodium metabolism may be critical in the causation of certain forms of hypertension, particularly salt-sensitive hypertension. Long-term restriction of sodium intake in patients at high risk for the development of hypertension may reduce the chances of established hypertension occurring later. These high-risk patients in whom subsequent hypertension may be prevented include normotensive patients with family histories of hypertension, elderly patients, black patients, and those with low-renin hypertension. Treatment of hypertension with moderate sodium restriction to 70 mEq/day will significantly reduce blood pressure in a large percentage of patients, particularly known salt-sensitive hypertensive patients. This degree of restriction is also an effective adjunctive therapy for patients receiving antihypertensive medications. There is convincing experimental, epidemiologic, and clinical evidence that moderate sodium restriction helps prevent and assists in the treatment of hypertension in those patients who are genetically predisposed to develop primary hypertension or who already have hypertension. There is no evidence that this degree of sodium restriction is harmful."