Prolactin

Prolactin is a pituitary gland hormone that causes the breasts to grow and produce milk. If prolactin levels are higher than normal, it often means there is a type of tumor of the pituitary gland. This test is often used to diagnose a prolactinoma, find the cause of a woman’s menstrual irregularities and/or infertility, or determine the reason for a man’s low sex drive and/or erectile dysfunction.