I wasn't sure how to register my vote, but I agree with those who said that there is no known cause. However, here is something for all of you to consider. I was raised in a small Illinois town which was surrounded by oil refineries, a chemical plant, a glassworks, an ammunition plant, etc. When I attended my 30th class reunion (yes, I'm feeling old), my friend and I sat and discussed the HUGE number of us, all from the same little town, who are having these symptoms. Her Dr. has mentioned and ruled out arthritis, MS, Muscular Distophry, etc. There are several of our classmates who have either died of cancer, or are currently fighting it. I'm wondering if several of us might have Lupus, and if the environment in which we grew up might have something to do with it?