The term 'abnormally enlarged thyroid gland' refers to a condition known as goiter, which is characterized by an enlargement of the thyroid gland. Goiters can be caused by a variety of factors, including iodine deficiency and inflammation of the larynx. Iodine is an essential mineral for the production of thyroid hormones, and a lack of iodine can lead to goiter. The larynx is a part of the throat that helps to regulate breathing and speech, and inflammation of the larynx can also contribute to goiter.