Body fights itself: Immune system is meant to fight germs and foreign invaders. A healthy body recognizes its own cells and understands what are foreign cells and need fighting off. However, in some people the immune system is faulty in a way and it attacks normal cells, which is called as autoimmune disease.
Trial and error is common to diagnose the disease: Many autoimmune diseases affect various parts of the body and symptoms may come and go. It is difficult for experts to diagnose in such condition in one go.
Over 80 type of autoimmune diseases: There are over 80 types of autoimmune diseases. Some of such diseases are Celiac disease, Crohn's disease, endometriosis, Guillain-Barre syndrome, narcolepsy, psoriasis, and rheumatoid arthritis.
It is common: Many people suffer from autoimmune disorder.
It may be genetic: Autoimmune diseases can be genetic, but genes don't paint the whole picture. Environmental factors and infection play major role in triggering such diseases.
It is not allergy: Symptoms of autoimmune diseases are sometimes confused for allergic reactions; but it is not allergy.