Hypertension and the kidney.

Pathophysiologic and hereditary mechanisms impacting on the kidneys are crucial for the initiation and maintenance of essential hypertension. An appreciation of these renal mechanisms is important for the institution of appropriate antihypertensive therapy. The clinician must develop a physiologic algorithm to control systemic blood pressure while maintaining adequate blood supply to the kidneys. This approach is particularly important in patients at higher risk for progressive renal insufficiency (i.e., older patients, blacks, diabetics, and those with chronic renal failure). Better perfusion reduces the likelihood of activating the compensatory neurohormonal systems that augment the intrarenal effects of the renin-angiotensin-aldosterone and sympathetic nervous systems, which ultimately may be responsible for renal structural changes leading to nephrosclerosis. In addition, dietary concerns are also important, particularly in the patients with evidence of early renal disease. Controlling blood pressure in a physiologic way by using drugs that can potentially dampen neurohormonal systems may prevent or at least delay the development of nephrosclerosis. Thus, the clinician should use an individualized therapeutic approach to the patient with hypertension. If nonpharmacologic means of blood pressure control are unsuccessful, an attempt should be made to blend the specific physiologic needs of the patient with specified pharmacologic antihypertensive mechanisms, paying particular attention to the preservation of renal function and perfusion.