The main hormones that are created by the thyroid gland are thyroxin (T4) and triiodothyronine. However, the thyroid gland does not secrete a standard dose of these hormones automatically. The signal for this comes from a region of the brain called the hypothalamus, which secretes a hormone called Thyrotropin Releasing Hormne or TRH. This is then sent to the pituitary gland via dedicated artery stimulating the release of Thyroid Stimulating Hormone or TSH. This is the hormone that finally stimulates the thyroid gland to start producing T3 and T4. The reason why your tests are conducted for T3, T4, and TSH is to specifically identify which level is deficient and therefore where the problem lies. In all cases, it looks like you might have been given the standard treatment of levothyroxin only. This is a synthetic version of T4. There is some controversy in the medical community about whether it also makes sense to administer the synthetic version of T3 as well. This is because of conflicting results on the effectiveness of administering this as well.
Ideally, you should get your tests done again because of a number of reasons including finding out where your hormone levels are at now. A fresh test would be a good indicate of how much healthier you are now and therefore would be more accurate. Additionally, in some kind of an emergency, you must have the latest reports available so that the doctor can treat you accordingly. It is also important that you conduct a few more tests including those for prolactin levels. This is a hormone that is responsible for milk creation in the breasts and is present in both men and women. Curiously, it is also an indicator or pituitary function. From your own health perspective, you need to consume more seafood to ensure that there is enough iodine available in your system to create the thyroid hormones.
answered by M W