Addison's disease occurs due to a failure to produce adequate amounts of glucocorticoid and mineralocorticoid hormones from the adrenal cortex. The majority of cases are '''primary''' and occur due to an autoimmune response directed at the endocrine cells of the adrenal glands, resulting in adrenocortical atrophy. This is an example of a [[Type IV Hypersensitivity|type IV (delayed type) hypersensitivity response]]. Smaller numbers of primary cases are caused by haemorrhage, necrosis or neoplasia within the adrenal glands. '''Secondary''' hypoadrenocorticism occurs due to a reduction in the secretion of ACTH from the anterior pituitary gland. | Addison's disease occurs due to a failure to produce adequate amounts of glucocorticoid and mineralocorticoid hormones from the adrenal cortex. The majority of cases are '''primary''' and occur due to an autoimmune response directed at the endocrine cells of the adrenal glands, resulting in adrenocortical atrophy. This is an example of a [[Type IV Hypersensitivity|type IV (delayed type) hypersensitivity response]]. Smaller numbers of primary cases are caused by haemorrhage, necrosis or neoplasia within the adrenal glands. '''Secondary''' hypoadrenocorticism occurs due to a reduction in the secretion of ACTH from the anterior pituitary gland. |