Before classifying hematuria as asymptomatic, the physician should be sure that there are no symptoms pointing to underlying disease. The laboratory workup includes urinalysis, clinical chemistry and renal function tests, and hematologic studies. Intravenous pyelography is done to demonstrate any structural abnormalities, and cystoscopy and retrograde pyelography may be necessary to diagnose hemorrhagic cystitis, tumors of the bladder or other portions of the urinary tract, or calculi not found on intravenous pyelography. If these steps have not determined the cause of bleeding, renal parenchymal disease is probably present and a renal biopsy is indicated. The most common lesions found on renal biopsy are focal proliferative glomerulonephritis and diffuse proliferative glomerulonephritis.