Galactorrhea is a milky nipple discharge unrelated to the normal milk production of breast-feeding. Galactorrhea is not a disease but it may be an indication of an underlying problem. It usually occurs in women, even in ones who have never had children or after menopause. However, galactorrhea can occur in men and even in infants.

Galactorrhea may result from excessive breast stimulation, side effects from medications or disorders of the pituitary gland. It can also be caused by increased levels of prolactin, the hormone that stimulates milk production.

In some cases, the cause of galactorrhea cannot be identified. The condition may resolve on its own.


Symptoms of galactorrhea include:

  • Persistent or intermittent milky nipple discharge without traces of blood
  • Nipple discharge involving multiple milk ducts
  • Spontaneously leaked or manually expressed nipple discharge
  • One or both breasts affected
  • Absent or irregular menstrual periods
  • Headaches or vision problems.

Nonmilky nipple discharge, particularly bloody, yellow or clear spontaneous discharge that comes from one duct or is associated with a lump, requires prompt medical attention, as it may be a sign of an underlying breast cancer.


Galactorrhea is often caused by too much prolactin. Prolactin is produced by the pituitary gland, a gland at the base of the brain that secretes and regulates several hormones.

Possible causes of galactorrhea include:

  • Medications (sedatives, antidepressants, antipsychotics and high blood pressure drugs)
  • Cocaine or opioid use
  • Herbal supplements (fennel, anise or fenugreek seed)
  • Birth control pills
  • Underactive thyroid (hypothyroidism)
  • Chronic kidney disease
  • Noncancerous pituitary tumor (prolactinoma) or other disorder of the pituitary gland
  • Excessive breast stimulation (such as from sexual activity, frequent breast self-exams, chest rash, prolonged clothing friction)
  • Nerve damage to the chest wall (such as from surgery, burns or other chest injuries)
  • Spinal cord surgery, injury or tumors

Idiopathic galactorrhea

Galactorrhea without an identified cause is called idiopathic galactorrhea. This may mean that the breast tissue is particularly sensitive to the milk-producing hormone prolactin in the blood.

Galactorrhea in men

Galactorrhea in men may be associated with testosterone deficiency (male hypogonadism) and it usually occurs with breast enlargement or tenderness (gynecomastia). Erectile dysfunction and a lack of sexual desire are also associated with testosterone deficiency.

Galactorrhea in newborns

Galactorrhea can sometimes occur in newborns. This may be the result of high maternal estrogen levels crossing the placenta into the baby’s blood. This may cause enlargement of the baby’s breast tissue, which may lead to a milky nipple discharge.