Prolactin Blood Test

As well as producing breast milk, prolactin has other wide ranging functions in the body, from influencing the reproductive system to regulating the immune system. Sometimes both men and non-pregnant or breast feeding women can have raised prolactin and this can cause a milky discharge from the nipple in both sexes (though rarely in men). Commonly this is caused by a prolactinoma, a normally benign (not cancerous) tumour of the pituitary gland which can cause symptoms of headaches and visual impairment. 

Other causes of raised prolactin can include polycystic ovaries, hypothyroidism, kidney disease and anorexia. Certain drugs and anabolic steroids can also cause high prolactin levels. Elevated prolactin in women can result in infertility, breast tenderness and irregular periods, while it men in can cause low libido and enlarged and tender breasts.