The term goiter simply refers to the abnormal enlargement of the thyroid gland. In other words, it means "enlarged thyroid." A goiter can occur in a gland that is producing too much hormone (hyperthyroidism), too little hormone (hypothyroidism), or the correct amount of hormone (euthyroidism). A goiter indicates there is a condition present which is causing the thyroid to grow abnormally. Worldwide, the most common cause of goiter is iodine deficiency, a condition that is not typically found in the United States. A goiter can be a general enlargement of the thyroid without nodules (as is commonly seen in Graves' disease), Hashimoto's thyroiditis, or other causes of thyroid inflammation. A nodular goiter is seen when the enlargement is due to the presence of nodules or cysts. Goiters may be associated with an underactive or overactive thyroid condition, but most often normal thyroid function is seen.

Treatment will depend upon the cause of the goiter. If the goiter is due to a deficiency of iodine in the diet (not common in the United States), iodine supplementation may be prescribed. This will lead to a reduction in the size of the goiter, but often the goiter will not completely resolve. If the goiter is due to Hashimoto's thyroiditis, and you are hypothyroid, you will be given thyroid hormone supplement as a daily pill. If the goiter is due to hyperthyroidism, the treatment will depend upon the cause of the hyperthyroidism. Many goiters, such as the multinodular goiter, are associated with normal levels of thyroid hormone in the blood. These goiters usually do not require any specific treatment after the appropriate diagnosis is made. If no specific treatment is suggested, you may be warned about the risk for becoming hypothyroid or hyperthyroid in the future. However, if there are problems associated with the size of the thyroid, such as the goiter getting so large that it constricts the airway, surgical removal of the goiter may be necessary.