In this case, however, instead of causing prolonged overproduction of thyroid hormones, the autoantibodies eventually destroy the gland, preventing it from producing the hormones, and therefore producing permanent hypothyroidism. The picture can be complicated by the fact that occasionally the inflammation causes the release of enough of the hormones stored in the gland that it will produce a temporary state of hyperthyroidism. This is usually mild, should not cause bulging or protruding eyes, and is inevitably followed by hypothyroidism because of the destruction of the gland. Why some people will produce autoantibodies which stimulate the gland and cause hyperthyroidism, while others produce autoantibodies which slowly destroy the gland and produce hypothyroidism, is not known. Both conditions are readily treated.
Hypothyroidism requires simply the replacement of the missing thyroid hormones.
Some T4 is transformed in the body into T3, so taking only the one hormone replaces both for most people. There are no plant or herbal sources of these hormones that I am aware of. Taking iodine in vitamins or as separate pills will not treat hypothyroidism, since the problem lies not with the supply of iodine, but with the body's ability to form it into the hormones T4 and T3. In fact excessive iodine can be harmful in some situations. The treatment of Graves' disease is more complicated, and may involve pills, radioactive iodine or, occasionally, surgery.