Hello! Galactorrhea has different causes, like hyperprolactinemia. Prolactine is the hormone that stimulates milk production, and is secreted by the pituitary gland wich is found in the brain. There are some pituitary tumors that produce increased levels of prolactine, and are called prolactinoma. In general those are benign and are treated frequently by medication or surgery. Other causes of galactorrhea are the use of some drugs like antidepressants or antipsychotics, high blood pressure drugs, birth control pills, use of recreational substances cocaine, marijuana or opioids, chronic kidney disease, spinal cord diseases, or even excessive physical stimulation of the breasts. In some cases the galactorrhea is idiopathic, without finding out the cause. I would suggest to make an appointment with an endocrinologist to measure at first the blood level of prolactine. I hope i have been of help