Why are autoimmune diseases increasing?

Autoimmune diseases, in which the body's defense mechanisms get confused and attack their own healthy cells, have been around since day one. There are many types of autoimmune conditions, such as rheumatoid arthritis and type 1 diabetes, and they really are nothing new. What is new, however, is the number of people suffering from them. For decades now, the incidence of autoimmune diseases has been on the rise, and scientists are trying to work out why.Curious? Check out this gallery to learn more.