What is the primary cause of primary adrenal insufficiency (Addison's disease)?

In primary adrenal insufficiency, also known as Addison's disease, the primary underlying cause often involves adrenal atrophy due to autoimmune processes. This condition occurs when the body's immune system mistakenly attacks the adrenal glands, leading to decreased production of adrenal hormones, specifically cortisol and aldosterone. The autoimmune destruction typically targets the adrenal cortex, resulting in the classic symptoms associated with Addison's disease, such as fatigue, weight loss, and hypotension.

While chronic infections like tuberculosis can indeed affect the adrenal glands and lead to adrenal insufficiency, this is more commonly viewed as a secondary cause rather than the primary cause of Addison's disease. Excessive secretion of adrenocorticotropic hormone (ACTH) can occur in secondary adrenal insufficiency, which is not specific to Addison's disease but rather indicates a problem with the pituitary gland or hypothalamus. Likewise, bilateral adrenal hemorrhage is a rare condition that can lead to acute adrenal insufficiency but is not considered the primary etiology of Addison's disease itself.