check your daily vitamin for iodine- I'd been having some minor thyroid issues (not enough to justify meds when I don't have insurance, but enough to wreak havoc on my life) and I recently discovered the vitamins I was on have no Iodine in them (you need iodine for you thyroid to work properly) I had to check every bottle of vitamins in the store till I found one that had iodine in it.
there were a couple of really good articles I read on Web-MD about iodine and your thyroid, about how there isn't actualy as much in table salt as there is supposed to be, and because of the processed foods (made without iodized salt) and being told to cut back on salt, most americans wouldn't get enough iodine even if the levels were where they are supposed to be. It also mentioned that drinking floridated water interferes with the body's use of iodine.
There are several good natural sources for Iodine as well- many seafoods, especial specific types of sea-weed (bladderwrack being the best, but difficult to find).