Found on the pituitary gland, prolactinoma is a non-cancerous tumor that causes the body to overproduce the hormone prolactin which stimulates breast milk. It decreases levels of estrogen for women and testosterone for men. Prolactinoma is not life-threatening but, if left untreated, it can cause infertility and impaired vision. It is the most common type of tumor found in the pituitary gland. Symptoms include unexplained breast milk in women who are not pregnant or nursing, changes in menstruation and decreased sexual interest. The symptoms are less obvious in men which can often delay a visit to the doctor. Men experiencing erectile dysfunction, headaches and problems with their vision should make appointment with their doctor. Doctors use drug therapy to effectively restore prolactin levels in the body. Surgery and radiation may also be used to remove the tumor.