I was sure I had Fibromyalgia; my joints and muscles were always inflamed and by the end of the day I could hardly walk. It turns out I actually have Celiac disease which is also an autoimmune disorder, but by eliminating gluten from my diet, I felt 100% better in just one week. I have felt like crap for 7 years and can't believe I didn't try eliminating wheat sooner. If you have joint and muscle pain and other symptoms of Fibro, it's definitely worth a try and very easy.
I've had CFS for about 6 years and in the past few months I've made a remarkable recovery. In my case underlying causes were food sensitivities (dairy and corn) and PBB poisoning as well as metal toxicity. In Michigan in the 70s a chemical company accidentally dumped PBB into cattle feed and it got into the food chain. Working with my kinesiologist I've done a lot of detoxing and now am up to about 75% of the energy I used to have. I got rid of my aluminum cookware. This year I'll have my metal (mercury) fillings replaced. The headaches and other conditions like IBS are gone. CFS and fibromyalgia seem to be related to the body being filled with toxins more than its able to handle. That explains why conventional medicine can't figure out what the cause it -- it's a different set of causes for every individual. Still, anything you can to do detox should help, and look for food intolerances as well.