Galactorrhea (guh-lack-toe-REE-uh) is a milky nipple discharge unrelated to the normal milk production of breast-feeding. Galactorrhea itself isn't a disease, but it could be a sign of an underlying problem. It usually occurs in women, even those who have never had children or after menopause. But galactorrhea can happen in men and even in infants.
Excessive breast stimulation, medication side effects or disorders of the pituitary gland all may contribute to galactorrhea. Often, galactorrhea results from increased levels of prolactin, the hormone that stimulates milk production.
Sometimes, the cause of galactorrhea can't be determined. The condition may resolve on its own.