Question: What causes Adrenal Insufficiency and Addison's Disease ?
Answer: A lack of CRH or ACTH causes secondary adrenal insufficiency. The lack of these hormones in the body can be traced to several possible sources. Stoppage of Corticosteroid Medication A temporary form of secondary adrenal insufficiency may occur when a person who has been taking a synthetic glucocorticoid hormone, called a corticosteroid, for a long time stops taking the medication. Corticosteroids are often prescribed to treat inflammatory illnesses such as rheumatoid arthritis, asthma, and ulcerative colitis. In this case, the prescription doses often cause higher levels than those normally achieved by the glucocorticoid hormones created by the body. When a person takes corticosteroids for prolonged periods, the adrenal glands produce less of their natural hormones. Once the prescription doses of corticosteroid are stopped, the adrenal glands may be slow to restart their production of the bodys glucocorticoids. To give the adrenal glands time to regain function and prevent adrenal insufficiency, prescription corticosteroid doses should be reduced gradually over a period of weeks or even months. Even with gradual reduction, the adrenal glands might not begin to function normally for some time, so a person who has recently stopped taking prescription corticosteroids should be watched carefully for symptoms of secondary adrenal insufficiency. Surgical Removal of Pituitary Tumors Another cause of secondary adrenal insufficiency is surgical removal of the usually noncancerous, ACTH-producing tumors of the pituitary gland that cause Cushings syndrome. Cushings syndrome is a hormonal disorder caused by prolonged exposure of the bodys tissues to high levels of the hormone cortisol. When the tumors are removed, the source of extra ACTH is suddenly gone and a replacement hormone must be taken until the bodys adrenal glands are able to resume their normal production of cortisol. The adrenal glands might not begin to function normally for some time, so a person who has had an ACTH-producing tumor removed and is going off of his or her prescription corticosteroid replacement hormone should be watched carefully for symptoms of adrenal insufficiency. More information is provided in the NIDDK health topic, Cushings Syndrome. Changes in the Pituitary Gland Less commonly, secondary adrenal insufficiency occurs when the pituitary gland either decreases in size or stops producing ACTH. These events can result from - tumors or an infection in the pituitary - loss of blood flow to the pituitary - radiation for the treatment of pituitary or nearby tumors - surgical removal of parts of the hypothalamus - surgical removal of the pituitary
Source: NIDDK