Treatment may not be necessary if the goitre is small. Goitre may be related to hyper- and hypothyroidism (especially Graves' disease) and may be reversed by treatment. Graves' disease can be corrected with antithyroid drugs (such as propylthiouracil and methimazole), thyroidectomy (surgical removal of the thyroid gland), and iodine-131 (131I - a radioactive isotope of iodine that is absorbed by the thyroid gland and destroys it). Hypothyroidism may raise the risk of goitre because it usually increases the production of TRH and TSH. Levothyroxine, used to treat hypothyroidism, can also be used in euthyroid patients for the treatment of goitre. Levothyroxine suppressive therapy decreases the production of TRH and TSH and may reduce goitre, thyroid nodules, and thyroid cancer. Blood tests are needed to ensure that TSH is still in range and the patient has not become subclinically hyperthyroid. If TSH levels are not carefully monitored, it is alleged that levothyroxine may increase the risk of osteoporosis but no peer reviewed studies on levothyroxine replacement of Hypothyroid patients causing this effect have actually been produced.
Thyroidectomy with 131I may be necessary in euthyroid goitrous patients who do not respond to levothyroxine treatment, especially if the patients have difficulty breathing or swallowing. 131I, with or without the pre-injection of synthetic TSH, can relieve obstruction and reduce the size of the goitre by thirty to sixty-five percent. Depending on how large the goitre is and how much of the thyroid gland must be removed or destroyed, thyroidectomy or 131I may produce hypothyroidism requiring life-long treatment and may eventually lead to death.
[edit] Epidemiology
Iodine is necessary for the synthesis of the thyroid hormones thyroxine (T4) and triiodothyronine (T3). In endemic goitre, iodine deficiency leaves the thyroid gland unable to produce its hormones because the mature hormone molecules require iodine atoms to be attached. When levels of thyroid hormones fall, thyrotropin-releasing hormone (TRH) is produced by the hypothalamus. TRH then prompts the pituitary gland to make thyrotropin or thyroid stimulating hormone (TSH), which stimulates the thyroid gland’s production of T4 and T3. It also causes the thyroid gland to grow in size by increasing cell division.
Goitre is more common among women, but this includes the many types of goitre caused by autoimmune problems, and not only those caused by simple lack of iodine.
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