Hyperprolactinemia is a condition of elevated levels of the hormone prolactin in the blood. Prolactin is normally produced by the pituitary gland and its main functions are to induce breast development during pregnancy and stimulate lactation. Common causes of hyperprolactinemia include pregnancy, medications that affect dopamine levels, hypothyroidism, and pituitary tumors. Symptoms in women include galactorrhea (non-pregnancy related breast milk production), menstrual irregularities, and infertility. Treatment options aim to suppress prolactin levels and reduce tumor size, with dopamine agonists being the first-line medical treatment.