A tumor of the pituitary gland that isn't cancer but can cause vision problems, infertility and other health issues.

Prolactinoma affects the pituitary gland. The pituitary gland makes hormones that help control important functions throughout the body. The tumor causes this small gland at the base of the brain to make too much of a hormone called prolactin. That leads to lower levels of the sex hormones estrogen and testosterone. The exact cause of prolactinoma isn't clear.

Having too much prolactin in the blood can cause infertility, weak and brittle bones, and less interest in sex. It also can cause symptoms that are specific to the sex a person is assigned at birth. Growth of the prolactinoma tumor can lead to vision problems, headaches and lower levels of other hormones made by the pituitary gland.

With prolactinoma, medicines taken by mouth can shrink the tumor and cause it to make less prolactin hormone. Surgery to remove the tumor may be a treatment option if the medicine doesn't work or if its side effects are too harsh. Rarely, radiation therapy might be used to kill tumor cells in a large prolactinoma.