Causes of Adrenal Insufficiency
Causes of adrenal insufficiency may involve destruction of the adrenal cortex or a lack of adrenocorticotropic hormone (ACTH). The cause of primary adrenal insufficiency is due to a disorder of the adrenal glands themselves, in which both cortisol and aldosterone hormones are missing. Secondary adrenal insufficiency is the more common of the two types, and is caused by inadequate secretion of ACTH by the pituitary gland. Other causes of adrenal insufficiency include chronic infection, spreading cancer cells, and tumors.
Failure to produce adequate levels of adrenal hormones can occur for different reasons. The problem may be due to a disorder of the adrenal glands themselves (primary adrenal insufficiency) or to inadequate secretion of ACTH by the pituitary gland (secondary adrenal insufficiency).
Primary adrenal insufficiency (also known as Addison's disease) occurs because of the destruction of the adrenal cortex. As a result, both cortisol and aldosterone hormones are often lacking. Addison's disease symptoms usually begin when at least 90 percent of the adrenal cortex has been destroyed.
In about 70 percent of primary adrenal insufficiency cases, the destruction of the adrenal cortex is caused by the body's own immune system (autoimmune disease). Normally, the immune system protects the body against infection and disease. In an autoimmune disease, the body's immune system mistakenly attacks some part of your own body. In primary adrenal insufficiency, the immune system attacks the adrenal cortex. It is not known why the immune system attacks the adrenal cortex.
Other causes of primary adrenal insufficiency can include:
- Chronic infection (mainly fungal infections)
- Cancer cells spreading from other parts of the body to the adrenal glands (especially breast cancer)
- Sarcoidosis, amyloidosis, and hemochromatosis
- Surgical removal of the adrenal glands.