Bleeding is the loss of blood. It can be external, or outside the body, like when you get a cut or wound. It can also be internal, or inside the body, like when you have an injury to an internal organ. Normal vaginal bleeding is the periodic blood that flows as a discharge from the woman's uterus. Normal (menstrual) vaginal bleeding is also called menorrhea. The process by which menorrhea occurs is called menstruation. Normal vaginal bleeding occurs because of cyclic hormonal changes.