What is an enlarged thyroid gland called?

An enlarged thyroid gland is called a goiter, also spelled goitre. The enlargement appears as a swelling at the front or base of the neck and can affect part or all of the thyroid.

A goiter is a description of thyroid size, not a diagnosis of thyroid function. A person can have a goiter with normal hormone production, an underactive thyroid called hypothyroidism, or an overactive thyroid called hyperthyroidism. Goiters may be diffuse, involving the whole gland, or nodular, involving one or more lumps.

Historically, iodine deficiency has been one of the leading causes of goiter because the thyroid needs iodine to make its hormones. Worldwide, iodine deficiency accounts for more than 90% of goiter cases in the cited overview, although autoimmune disease, thyroid nodules, tumors, and certain medications can also contribute. Iodized salt has greatly reduced deficiency-related goiter in many countries.

The word comes from the Latin gutturia, meaning “throat.” The related terms in the answer choices are different: thyroiditis means inflammation, while hypothyroidism and hyperthyroidism describe hormone activity rather than enlargement itself.