Various causes of pituitary cell destruction and hypofunction can lead to hypopituitarism, usually more than 50% of the pituitary tissue destruction before symptoms appear, 75% of the destruction before there are obvious clinical symptoms, to be destroyed up to 95% of the serious pituitary hypofunction. The most common cause of pituitary lesions in adults is pituitary tumors, which can compress normal pituitary tissues and reduce their function. The next is ischemic necrosis of the pituitary gland, mainly seen in pregnancy and childbirth hemorrhage caused by the Sheehan syndrome. In addition, surgery, radiation therapy, trauma, infection and inflammation in the butterfly saddle area can cause damage to the normal pituitary tissues. 2, hypothalamic lesions: such as tumors, inflammation, infiltrative lesions (such as lymphoma, leukemia), granulomas (such as nodular disease), etc., can directly destroy the hypothalamic neurosecretory cells, so that the release of hormone secretion is reduced. 3, long-term treatment with glucocorticoids can inhibit hypothalamic CRH-pituitary ACTH, and medical source hypopituitarism can occur after sudden discontinuation of glucocorticoids, manifesting as hyperalgesia. 4, Other: autoimmune pituitary inflammation, vacuolated saddle, and internal carotid aneurysm at the cavernous sinus may also compress the pituitary gland. Metastasis of other malignant tumors.