[Differential diagnosis of urinary findings]

Classical urinalysis is extremely useful in the differential diagnosis of diseases of the kidneys and lower urinary tract. Although dipsticks are suitable for orientational purposes, when pathology is indicated, and when renal disease presents, they must be supplemented by urine microscopy or quantitative and qualitative protein electrophoresis to establish the diagnosis. Phase-contrast microscopy can distinguish glomerular from nonglomerular hematuria and thus guide the further diagnosis, and the detection of leukocytes and bacteria confirms the diagnosis of urinary tract infection. In asymptomatic patients microhematuria or proteinuria is detected more frequently with increasing age. A differentiated diagnostic strategy must be adapted to the individual risk of the patient, and must avoid overdiagnosis while not missing potentially serious pathology.