Kelly, I am there right now and having the worst flare of costo ever. I have posted about it on the fibromyalgia board also. As far as thyroid is concerned, all I've been told is that I have thyroiditis and a couple of small nodules. My labs are always within normal ranges, which means everything is okay according to most doctors, but IMO my labs indicate I am heading towards hypo. I don't remember having the antibodies test, but I do recall one doctor telling me that I have them. It would just be my guess that I have Hashi's. If I do, then it appears that costo is one of my symptoms. In any event, I've tried all kinds of things for relief but have found the best thing for me is magnesium, ice or heat packs and rest, rest, rest. I share your pain. It's just an awful curse and I hope you get relief soon. BTW - what type of thyroid problem are you dealing with???