Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (239 page)

   Vaginal bleeding (menstruation)

   Viral illness

   Bacteriuria

   Certain foods (beets, blackberries, rhubarb)

   Pigmenturia (myoglobin, porphyrin, hemoglobin)

   Drugs (rifampin, phenolphthalein, iodides, bromides, copper, oxidizing agents, permanganate)

   Postejaculate semen

   Red diaper syndrome

   Trauma

   Vigorous exercise prior to collection

   pH > 9

   Factitious

   Causes of false-negative results

   Reducing agents (high doses of vitamin C)