Prolactin secretion is influenced by many factors, including physiologic factors (e.g., pregnancy, sleep and stress), pathologic factors (e.g., pituitary adenoma, hypothyroidism and renal failure), and some drugs (e.g., antipsychotics, antidepressants, prokinetics, morphine and antihypertensive agents). Here, PRL is linked to pituitary gland adenoma.