PIP: Galactorrhea refers to the secretion of a milky fluid from the breast, occurring either spontaneously or with manual expression, in the absence of pregnancy or the postpartum state. The development of a sensitive and specific radioimmunoassay for human prolactin during the last decade along with improved neuroradiologic techniques have greatly expanded understanding of nonpuerperal lactation. Discussion reviews the pevalence of galactorrhea, the etiology of hyperprolactinemia and/or galactorrhea, pituitary tumor, parapituitary lesions, oral contraceptive (OC) associated galactorrhea, drug induced galactorrhea, hypothyroidism, neurogenic stimulation, idiopathic galactorrhea, clinical features of galactorrhea, laboratory evaluation, neuroradiologic evaluation, hypocycloidal tomography, carotid angiography, pneumoencelphalography (PEG), computerized tomography (CT), management, and therapy. The prevalence of galactorrhea in women is reported to range from 0.1-32%. Much of this variability can be attributed to differences in examination techniques, the investigator's definition of galactorrhea, and the patient population studied. Nonpuerperal hyperprolactinemia is an important cause of galactorrhea and is found in 49-77% of cases, but hyperprolactinemia does not appear to be the sole prerequisite for galactorrhea since only 15-68% of patients with excessive prolactin secretion develop galactorrhea. Pituitary tumors are the most important diagnostic consideration have been reported in approximately 20% of cases of galactorrhea and 34% of cases of amenorrhea galactorrhea. Parapituitary lesions, an infrequent but important cause of hyperprolactinema and galactorrhea, can result in excessive prolactin secretion by interfering with either the production or delivery of prolactin inhibitory factor to the lactotrope cells of the anterior pituitary gland. OC associated galactorrhea is a frequent diagnosis in patients with nonpuerperal lactation and has been implicated in 10-14% of cases. OC discontinuation can also produce galactorrhea. Pharmacologic agents are a common cause of hyperprolactinemia and/or galactorrhea. A variety of forms of neurogenic stimulation have been linked to hyperprolactinemia and/or galactorrhea. Idiopathic galactorrhea is a diagnosis of exclusion and is applicable to 40-50% of patients with nonpuerperal lactation. In patients with galactorrhea, the presence of the abnormal, milky breast secretion may be the sole symptom or it may be associated with other pertinent clinical findings. All patients with galactorrhea should have measurements of thyroid stimulating hormone and serum prolactin performed. The optimal management of patients with prolactinomas is somewhat controversial. Surgical resection remains the most definitive form of therapy with the transsphenoidal approach most frequently used. Recent invesitgations show promise for bromocriptine as an alternative therapeutic modality.