Prolactin is a hormone that is produced by the   pituitary gland and although it also forms part of the   stress hormone circuit, it plays a vital role in breast development during pregnancy and the production of breast milk after giving birth.
Abnormally high levels of prolactin, which is referred to as hyperprolactinemia, causes disruptions in the normal menstrual cycle, anovulatory cycles, infertility and the   production and spontaneous flow of breast milk in women who are not pregnant or breastfeeding a baby. […]