The prognostic significance of proteinuria when discovered incidentally in asymptomatic young adults remains unknown. When other evidence of renal disease such as an abnormal urinary sediment, hypertension, or elevation of the blood urea nitrogen (BUN) and creatinine is present, then the proteinuria becomes merely one manifestation of diffuse kidney malfunction and the prognosis becomes that of the underlying renal disease.
Isolated proteinuria is a more difficult problem. Earlier investigators distinguished between constant proteinuria, which they considered indicative of underlying renal disease and, therefore, a bad prognostic omen, and intermittent proteinuria, which they felt was almost universally a benign condition. However,