I take it that symposiums on hematuria are held to stress primarily the grave significance of blood in the urine. In very exceptional cases, a correct diagnosis can be made on the gross characteristics of the hematuria alone. In the vast majority of instances, hematuria merely indicates to the experienced observer the necessity for a complete urologic study, without which neither the cause nor the source of the bleeding can be determined with certainty.
The term hematuria, which is defined as the discharge of urine containing whole blood, implies no differentiation between gross and microscopic amounts of blood. The occasional finding of a few red blood cells in the routine study of the urine is not uncommon in the absence of surgical affections of the genito-urinary organs, so that, unless the blood is persistent or is associated with other symptoms, it has little clinical significance. The persistent presence of even