@jazzticity Think about it like this. When a person is stung by a bee, there is typically an immune response, some inflammation at the sting site, maybe some itching. This is fighter cells responding to a foreign substance in the body. Sometimes the immune response is much more than necessary, and way to many histamines are released. The body feels like it is doing the right think by fighting, but it actually works against the person and they swell too much, throat my close up, and they can die. Each time the body gets better at responded to the next bee sting, and each time a bee sting is more deadly for that person.
Too much of an immune response can cause fevers so high it leaves the patient with brain damage, but the body is actually attacking the bacteria or virus, or flooding of tissues, all sorts of body gone haywire things.
When it comes to autoimmune it is considered to be the body attacking itself. The theory is it sees its own organism as a foreign body. So, a hyperstimulated immune system means there might be more chance of an autoimmune response if the self begins to wrongly recognize something that should be ok.
Personally, I believe eventually many many autoimmune diseases will be discovered to actually have an antagonist. This is my own theory, I am not a doctor, but I will give you some examples. Lymes disease was originally being observed as an arthritic type of disease scene in many children in Lyme, CT. They treated the children as they would with other arthritis diseases. Finally research was done and a bacteria was isolated, and they realized it was not an autoimmune disease, but the bodies reaction to this particular germ. The thing is, some people with Lymes are much sicker than others. Depends on the individuals immune system.
Other examples are stomach ulcers, which were later found to be bacterial infection after years of people thinking the body was producing too much stomach acid, or the patient was not coping with stress well. But, many people are asymptomatic with the bacteria that causes stomach ulcers, while others wind up with bleeding stomachs. Rheumatic Heart is another, there are many examples.
So, the immune system is a delicate thing. We want the body to respond to foreign agents, but not too much.