Addison’s disease is an uncommon autoimmune disease, characterized by chronic and insufficient functioning of the outer layer of the adrenal gland. The adrenal glands are located atop each kidney and produce vital glucocorticoid hormones. Because of this chronic under-functioning of the adrenal glands, persons with Addison’s disease have a deficiency in the production of glucocorticoid hormones. Glucocorticoid hormones are involved in how the body utilizes and stores carbohydrates, protein, fat and blood sugar.
The adrenal gland also plays a role in the immune response. A deficiency in glucocorticoid hormones causes an increase in the release of sodium and a decreased release of potassium in the urine, sweat, saliva, stomach and intestines. These changes can cause low blood pressure and increased water excretion that can in some cases lead to severe dehydration.
Although there are many underlying factors in the development of adrenal insufficiencies, including destruction of the adrenal cortex due to diseases such as tuberculosis, the growth of tumors, non-autoimmune diseases amyloidosis and adrenoleukodystrophy, and atrophy of the gland due to prolonged use of cortical steroids used in the treatment of other conditions and illnesses, most cases of Addison’s disease are thought to be autoimmune in nature.