I think most autoimmune diseases are caused by a bunch of factors working together to make a perfect storm. Two of the factors I know about that led to my MG are a genetic predisposition to autoimmune diseases and a bout with the flu (H1N1). In general, viral or bacterial infections can cause the immune system to overreact in some people--especially long-standing infections.

But from what I've read here, my story is unusual. Most people who have MG can't point to specific triggers.

Abby