About the Thyroid Gland
What is the Thyroid Gland?
The thyroid gland is a small, soft, butterfly-shaped gland located in the lower portion of the neck. The thyroid drapes over the trachea (windpipe) on three sides. The esophagus is situated behind the trachea.
Your body produces many hormones used to help regulate the many complex processes occurring every second in your body. The thyroid gland produces hormones that help control the function of many of your body's organs and your metabolism. The thyroid helps regulate how your body metabolizes (processes) proteins, fats, carbohydrates and vitamins, and helps determine your body's overall temperature. Thyroid hormones are also important in helping the body produce and use other hormones and chemicals, such as adrenaline, epinephrine and dopamine.
To make these important hormones, the thyroid uses iodine, which is ingested in the food you eat. Iodine is found in iodized table salt, bread, milk and seafood and other foods. Your thyroid removes the iodine from your blood and uses it to make two kinds of thyroid hormone: Thyroxine (T4) because it has 4 iodine molecules and Triiodothyronine (T3) since it has 3 iodine molecules.
The Pituitary Gland
Production of thyroid hormone by the thyroid gland is regulated by another hormone that is made by the pituitary gland (a small gland in the base of your brain). The pituitary gland makes Thyroid-Stimulating Hormone (TSH). TSH travels from the pituitary gland to the thyroid gland to tell the thyroid when to produce thyroid hormone for the rest of the body.
The pituitary and thyroid glands work together to produce the right amount of thyroid hormone (T3 or T4) for the body. If the body needs more thyroid hormone, the pituitary will increase production of TSH to stimulate production of thyroid hormone from the thyroid gland. If the body has enough thyroid hormone, or makes too much, the pituitary will make less TSH.
Hypothyroidism and Hyperthyroidism
Sometimes production of thyroid hormone can become unbalanced. People are considered hypothyroid when they produce too little thyroid hormone and hyperthyroid when they produce an excess. In hypothyroid patients, the TSH level is elevated, and in those with hyperthyroidism the TSH level is low. Thyroid hormone and TSH work opposite of one another. There are many causes for hypo- and hyperthyroidism. In general, hypothyroidism is treated with medication. For those with hyperthyroidism, there are several different treatment options depending on the cause.