Addison’s disease is a severe or total deficiency of the hormones made in the adrenal cortex, caused by a destruction of the adrenal cortex. There are normally two adrenal glands, located above each kidney. The adrenal glands are really two endocrine ( ductless or hormone producing ) glands in one. The inner part of the adrenal ( called the medulla ) produces epinephrine ( also called adrenaline ) which is produced at times of stress and helps the body respond to “fight or flight” situations by raising the pulse rate, adjusting blood flow, and raising blood sugar. However, the absence of the adrenal medulla and epinephrine does not cause disease.
In contrast, the outer portion of the adrenal, the cortex, is more critical. The adrenal cortex makes two important steroid hormones, cortisol and aldosterone. Cortisol mobilizes nutrients, modifies the body’s response to inflammation, stimulates the liver to raise the blood sugar, and also helps to control the amount of water in the body. Aldosterone regulates salt and water levels which affects blood volume and blood pressure. Cortisol production is regulated by another hormone, adrenocorticotrophic hormone (ACTH), made in the pituitary gland which is located just below the brain. Classical Addison’s disease results from a loss of both cortisol and aldosterone secretion due to the near total or total destruction of both adrenal glands. This condition is also called primary adrenal insufficiency. If ACTH is deficient, there will not be enough cortisol produced, although aldosterone may remain adequate. This is secondary adrenal insufficiency, which is distinctly different, but similar to Addison’s disease, since both include a loss of cortisol secretion.
Symptoms of Addison’s Disease