Prolactin is a hormone produced in the anterior lobe of the pituitary gland that helps control the menstrual cycle and lactation (breastfeeding). High levels cause sterility, amenorrhoea (no menstrual periods) and galactorrhoea (abnormal breast milk production). The normal levels in a blood sample are:-
|Female||3 to 25 µg/L (less than 600 mU/L)|
|Male||2 to 15 µg/L (less than 450 mU/L)|
High blood levels are found in tumours or enlargement of the pituitary gland under the brain, tumours of the brain that put pressure on the pituitary gland, brain injury, hypothyroidism (under active thyroid gland), kidney failure, sarcoidosis, pregnancy, Stein-Leventhal syndrome, severe premenstrual tension, stress, with some drugs (eg. phenothiazines, antidepressants, antihistamines) and with excess caffeine.