Galactorrhea or galactorrhoea is the spontaneous flow of milk from the breast, unassociated with childbirth or nursing. It can be due to local causes or dysregulation of certain hormones.
Lactation requires the presence of estrogen, progesterone and prolactin, and the evaluation of galactorrhea includes eliciting a history for various medications (methyldopa, opiates, some atypical antipsychotics) and for behavioral causes (including licorice, stress, and breast and chest wall stimulation), as well as evaluation for pregnancy, pituitary adenomas (with overproduction of prolactin or compression of the pituitary stalk), and hypothyroidism. Overproduction of prolactin leads to cessation of menstrual periods and infertility, which may be a diagnostic clue.
