Ace the 2026 ATI Pathophysiology Test – Dive Into Disease with Confidence!

An autoimmune disorder is defined as a condition in which the immune system mistakenly identifies the body's own cells as foreign or harmful and launches an attack against them. This misidentification leads to inflammation and damage to various tissues and organs. In autoimmune diseases, the immune response, which typically functions to defend the body against pathogens, turns against the very cells it is meant to protect, resulting in a range of symptoms and complications depending on which organs are affected.

For instance, in conditions like rheumatoid arthritis, the immune system targets the synovial tissue in joints, leading to pain and swelling. In type 1 diabetes, the immune system destroys insulin-producing beta cells in the pancreas. The hallmark of autoimmune disorders is this inappropriate immune response directed at the body’s own components, which is why option B accurately captures the essence of what defines these conditions.