Lactating but not pregnant: causes and symptoms?

So if you are a woman who's developed breast milk outside pregnancy, that could be related to high levels of prolactin. Prolactin is a normal hormone that's there to promote breast milk during pregnancy and in the post-partum period. But outside those times a high level of prolactin will provoke breast milk production. That's most commonly due to a small abnormality of the pituitary gland or the pituitary microadenoma that produces that excess prolactin. And that's a condition that needs to be investigated and defined but can be relatively easily treated with tablet therapy.