Drugs are a common cause of hyperprolactinaemia. The major tranquilisers e.g. chlorpromazine block the D2 dopamine receptor, releasing the inhibition on prolactin production.
A common cause of hyperprolactinaemia is a prolactin secreting tumour or prolactinoma.
Occasionally a craniopharyngioma or other tumour may compress the pituitary stalk or hypothalamus. This interrupts the hypothalamic dopaminergic inhibition of prolactin release.
Other causes of hyperprolactinaemia are rare.
Last reviewed 01/2018