I had mine tested because of rapid heart rate, which is a sign of hyperthyroidism, but I had hypothyroidism. I went on med for it, a year or two later I started having symptoms again so asked to have blood level checked test showed hyperthyroidism and level changed in 2wks which usually level is very slow to change which is why it isn't caught the first test. I saw an endochrinologist and tested for diseased thyroid but everything ok. a few weeks later it was back to hypothyroid levels. Dr said I had thyroiditis an inflammation of the thyroid. I was so mad because with hyperthyroidism you normally lose weight, have excessive energy, and not hair loss. I still was fat, depressed, and losing hair. Oh well that is how life goes, the funny part was I had to have a pregnancy test before they could give me radioactive isotopes for testing. My college age daughter was with me and thought it was hilarious and had to call her dad and tease him. At that age she hated to think her parents could be having sex.