Clinically apparent proteinuria in essential hypertension is associated with increased cardiovascular and total mortality and is an independent risk factor for cardiovascular and cerebrovascular disease. Subclinical elevation of urinary albumin excretion is seen more frequently than clinical proteinuria in essential hypertension and the levels of microalbuminuria (excretions of 30 to 300 mg/24 h) correlate with blood pressure. The increased urinary albumin excretion in hypertension may be explained by several factors such as renal hemodynamic changes, permselectivity changes of the glomerular filter, and structural arteriolar and glomerular changes due to nephrosclerosis. It has been clearly demonstrated that microalbuminuria is a risk factor for the development of clinical proteinuria, renal failure and increased cardiovascular mortality in insulin-dependent diabetes mellitus. It is still not known whether microalbuminuria also predicts development of proteinuria and decline in renal function in hypertension but there is some evidence indicating that microalbuminuria may be a marker of increased cardiovascular risk in hypertensives.