Primary hypoadrenalism or Addison's disease , or Addison's disease, results from failure of the adrenal glands themselves. This is usually an 'autoimmune' disease, where the immune system produces antibodies that attack tissues of the body rather than a virus or bacteria. In antibodies attack the adrenal cortex, causing damage and scarring. Antibodies to the adrenal cortex can be detected in the blood of some patients. Secondary hypoadrenalism or ACTH deficiency Secondary, or ACTH deficiency hypoadrenalism, is caused by diseases of the pituitary gland, which lead to adrenal failure as a secondary effect. Other causes Tuberculosis of the may also cause hypoadrenalism. This was a common cause of Addison's disease in Britain before the 20th century and remains a major cause in underdeveloped countries. Tuberculosis destroys the whole gland, both the cortex and the medulla. There are usually signs of tuberculosis in other organs, particularly the lungs. Destruction of the by tuberculosis is irreversible once hormonal deficiencies are clinically detectable. Rare causes Many rare diseases may affect the . In general, at least 80 per cent of both adrenal glands have to be damaged in order for deficiencies to become clinically evident. Rare conditions associated with primary and secondary include: Rare conditions associated with primary hypoadrenalism (a genetic disease in which the myelin sheath, or 'insulation', covering the nerve fibres within the brain is lost, along with degeneration of the adrenal gland). (a rare condition in which an abnormal substance called amyloid is laid down in various tissues, impairing their function). (surgical removal of the adrenal glands). (a common inherited condition in which an enzyme defect causes problems with the production of steroid hormones by the adrenal gland). Drugs (eg ketoconazole, metyrapone, mitotane). Familial glucocorticoid deficiency (ACTH receptor mutation). . Haemorrhage - usually in patients receiving anticoagulant drugs or in whom septicaemia ('blood poisoning') is present. inflammation. Metastases (spread of cancer from another part of the body. Sarcoidosis.
Rare conditions associated with secondary hypoadrenalism This means from causes acting on the pituitary gland rather than directly on the adrenal glands. The pituitary gland regulates adrenal cortisol production by responding to the amount of cortisol in the blood. However, the pituitary cannot distinguish between and synthetic steroid absorbed from medicines or steroid creams. If someone takes such treatment the pituitary production of will drop and as a result the adrenal cortex will become relatively inactive. If the steroid treatment is stopped abruptly then the patient may suddenly become deficient in cortisol as the adrenal gland takes some time - weeks or months - to regain its full manufacturing ability again. This is the reason that patients on medium or long-term steroid treatment are advised not to stop taking their medicine suddenly. Rarely, patients are affected by conditions that destroy the pituitary. Any cause of pituitary disease may cause deficiency. | 
