Hyperthyroidism: Graves' Disease, Toxic Nodular Goiter, and Solitary Toxic Nodule
Located in the lower portion of the neck, the thyroid gland produces thyroid hormones and is responsible for regulating the body’s metabolism. In patients with hyperthyroidism, the thyroid produces too much thyroid hormone, resulting in a variety of problems, including: nervousness, palpitations, increased sweating, irritability, tremor, unintentional weight loss, insomnia, and headaches. Patients who also suffer from hyperthyroidism caused by Graves’ disease may experience a change in the appearance of the eyes.
A diagnosis of hyperthyroidism is made when a blood test shows high levels of thyroid hormones and very low levels of thyroid-stimulating hormones (TSH), which is produced by the pituitary gland. When there are excessive levels of thyroid hormones in the bloodstream, the body’s normal feedback mechanism turns off the pituitary gland’s production of TSH, resulting in very low TSH levels.
The most common cause of hyperthyroidism is Graves’ disease, a condition marked by enlargement of the thyroid (also known as “goiter”), a bulging appearance to the eyes (“ophthalmopathy”), and sometimes changes to the skin along the legs.
Other causes of hyperthyroidism include Toxic Nodular Goiter, when multiple nodules in the thyroid produce too much thyroid hormone, and a Solitary Toxic Nodule, in which a single thyroid nodule produces excessive thyroid hormones. In cases of Toxic Nodular Goiter, significant enlargement of the thyroid can occur, causing the enlarged mass to press on surrounding structures, which can cause swallowing and breathing problems.
Patients diagnosed with hyperthyroidism are first evaluated and treated by endocrinologists, specialists in treating medical thyroid issues. The endocrinologist may order additional testing for hyperthyroidism, which may include a nuclear medicine scan.
Patients with hyperthyroidism are always initially treated with antithyroid drugs (methimazole and/or PTU), which inhibit thyroid hormone production by the thyroid gland. Although very effective, antithyroid medications are often needed for long periods of time to achieve remission and have some risk of mild to severe side effects. Sometimes beta-blockers are also prescribed to initially control the symptoms related to hyperthyroidism.
More definitive treatment options for hyperthyroidism include radioactive iodine therapy or surgery.
Radioactive iodine therapy is used to destroy thyroid tissue and can be effective in achieving a cure for some patients with hyperthyroidism. Patients with eye findings in Graves’ disease and those with compression symptoms are often not candidates for this treatment.
Surgical treatment for hyperthyroidism may be considered if there are co-existing thyroid enlargement nodules, known eye disease, and/or a preference to avoid radioactive iodine. In patients with Graves’ disease or Toxic Nodular Goiter, the entire thyroid gland is usually removed. In patients with a Toxic Solitary Nodule, the surgeon usually removes half of the thyroid.
Thyroid surgeons at Mass Eye and Ear have extensive experience and expertise in the surgical management of hyperthyroidism from the causes described. Using the latest surgical techniques including monitoring of the recurrent laryngeal nerve, surgeons can safely and thoroughly remove either the entire gland or a portion of the thyroid to achieve a permanent cure of hyperthyroidism.