Which condition is classified as an autoimmune disorder?

Hashimoto disease is classified as an autoimmune disorder because it involves the immune system attacking the thyroid gland, leading to hypothyroidism. In this condition, the body's own immune response mistakenly targets thyroid cells as foreign invaders, resulting in inflammation and reduced hormone production. This immune-mediated attack characterizes autoimmune disorders, where the body loses the ability to distinguish between its own tissues and those that are foreign.

The other conditions listed are not classified as autoimmune disorders. Addison disease, while it involves an autoimmune component in some cases, primarily refers to adrenal insufficiency. Cushing syndrome is typically a result of excess cortisol, often due to a tumor or prolonged use of corticosteroid medications, rather than an autoimmune reaction. Sheehan syndrome is related to pituitary gland failure following severe blood loss during childbirth, which does not involve an autoimmune mechanism. Understanding these distinctions clarifies why Hashimoto disease is appropriately identified as an autoimmune disorder.