The term “goiter” simply refers to an abnormally sized thyroid gland or the presence of more than one nodule within the thyroid gland of a normal size (called multinodular goiter). It is important to know that the presence of a goiter does not necessarily mean that the thyroid gland is malfunctioning. 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).  Iodine deficiency is the most common cause of goiter worldwide. In the United States, where significant iodine deficiency does not exist, multinodular goiter, chronic autoimmune (Hashimoto’s) thyroiditis, and Graves’ disease are more common causes of goiter. In older adults, multinodular goiter is most common.  Other less common causes of goiter include tumors, thyroiditis (thyroid inflammation), and other rare diseases. The risk of thyroid cancer within a multinodular goiter is approximately 3 to 5 percent.  Goiters can be managed well when evaluated, diagnosed and treated by a highly trained thyroid medical professional.