Autoimmune diseases are a class of disorders characterized by the immune system mistakenly attacking the body's own tissues and cells. This loss of self-tolerance results in chronic inflammation and damage to specific organ systems. The underlying mechanism involves a failure to distinguish between foreign invaders and native components, leading to the production of autoantibodies and an inflammatory cascade. While the precise etiology is complex, the development of these conditions is generally thought to result from an interplay between genetic predispositions and environmental triggers, which can activate immune responses against normally harmless self-antigens. Treatment generally focuses on managing symptoms, suppressing the overactive immune response, and mitigating tissue damage.