Hematuria: etiology and evaluation for the primary care physician.

Asymptomatic microscopic and gross hematuria are common problems for the primary care physician. The exact definition of microscopic hematuria is debated, but is defined by one group as > 3 red blood cells/high power microscopic field. While the causes of hematuria are extensive, the most common differential diagnosis for both microscopic and gross hematuria in adults includes infection, malignancy, and urolithiasis. Clinical evaluation of these patients often involves urological consultation with urine cytology, urine culture, imaging studies, and cystoscopy. Patients who have no identifiable cause after an extensive workup should be monitored for early detection of malignancy or occult renal disease.