If diagnosed early enough, the prognosis is typically excellent. If not, some tumors can grow into macroadenomas that press on the optic nerves (causing loss of peripheral vision and, in some cases, blindness), the brain (impacting function) and the pituitary (limiting or eliminating hormone production). Large tumors can also invade the cavernous sinuses, which house the carotid arteries, the veins to drain the eyes, and nerves involved in eye movement. Surgery around the cavernous sinuses is difficult and should be performed by an experienced pituitary surgeon. The tumors can also secrete too much of a hormone, causing hypertension, diabetes, mood disorders, sexual dysfunction, infertility, osteoporosis, arthritis, accelerated heart disease and death.