Cause
Addison's disease most commonly is caused by primary failure of the adrenal gland to secrete adequate amounts of mineralocorticoids, glucocorticoids, or both. It is thought that immune system-mediated destruction of the adrenal gland is the most common cause of primary adrenal gland failure. Other causes can include infection or inflammation in the adrenal gland; abnormalities in blood supply to the adrenal gland or bleeding within the gland; infiltration of cancer cells within the adrenal gland; the deposition of abnormal proteins within the adrenal gland; and physical trauma to the glands. Rapid withdrawal of drugs such as prednisone after chronic administration and overdoses of drugs used to treat Cushing's disease can result in adrenal gland failure. Secondary adrenal gland failure can occur due to primary problems in either the hypothalamus or the pituitary gland.