is an increase in thyroid
volume, visible in the form of a lump on the neck. A goiter is called "plunging" when it falls partly into the thorax. Plunging goiter is often associated with a change in thyroid hormones, especially an increase. This type of goiter is said to be compressive because it can cause respiratory symptoms including discomfort due to the compression of the trachea. Plunging goiter can be caused by a lack of iodine, by certain drugs
, or by the inflammation
of the thyroid. It requires a surgical operation to remove the entire thyroid gland.