Addison's disease, also known as primary adrenal insufficiency, is a rare long-term endocrine disorder characterized by inadequate production of the steroid hormones cortisol and aldosterone by the two outer layers of the cells of the adrenal glands, causing adrenal insufficiency. By: https://www.instagram.com/p/C_iaYVgoSg-/?igsh=MWFhcDZoNXVzbXBqdA==