[Hypertension and the kidneys]

The relationship between the kidneys and hypertension is multiple. Impaired renal function preventing adequate sodium excretion participates in the pathogenesis of primary hypertension. Renal diseases are the most frequent cause of secondary hypertension. Bilateral and unilateral parenchymatous affections predominate (5% of all hypertensions) over renovascular causes (2%). In the course of hypertension regardless of its etiology renal damage may develop--nephroangiosclerosis or atherosclerosis of the renal arteries with unilateral or bilateral affection (renal ischaemic disease). Hypertension is an important factor in progression of chronic renal diseases towards irreversible renal failure.