Galactorrhea refers to the unexpected release of milk from the breast outside of breastfeeding periods. This condition can stem from "normal" causes such as undetected pregnancy, surgery, excessive physical activity, or various medications, including cimetidine, female hormone replacement therapy, hydroxyzine, methyldopa, narcotics, reserpine, tricyclic antidepressants, or verapamil. Additionally, galactorrhea may arise from "abnormal" causes like liver disease, a phantom pregnancy (pseudocyesis), kidney failure, thyroid disorders, or a prolactinoma, which is a tumor that produces prolactin, the hormone responsible for milk production. The term "galactorrhea" is derived from the Greek words "galaktos," meaning "milk," and "rhein," meaning "to flow," translating to "milk flow." This condition is sometimes also referred to by another name.