Well before the COVID-19 pandemic, there were plenty of questions about autoimmune diseases. The 80 or so that have been identified can affect nearly every part of the body with a bewildering variety of symptoms. The diseases can be difficult to diagnose, and it is unclear what causes them. The concept of a disorder that causes the immune system, which is designed to protect us from foreign invaders, to launch an attack on healthy organs and tissues is mysterious and frightening.
