What does autoimmune mean?  

Body attacks itself. In autoimmune disease your immune system attacks your own body. This causes serious problems like colitis, thyroiditis, multiple sclerosis & lupus. There are often genetic predispositions but there is growing evidence that microbes and environmental toxins such as molds, heavy metals & pesticides play a key role. A well-written book on this is http://www.Donnajacksonnakazawa.Com/blog/?Page_id=7.
Self appears foreign. The body's immune system is designed to protect the body from foreign invaders like bacteria or unknown proteins. The body produces anti-bodies to fight the invading agent. In autoimmune conditions the body mistakenly produces anti-bodies to itself. When these self-antibodies attack the proteins they are directed against an inflammatory reaction occurs. The reaction causes symptoms like rashes.
Body attacks itself. Autoimmune means when your own immune system or antibodies unfortunately attacks itself. This occurs in disease such as lupus and type 1 diabetes.