The bulging in the throat that is due to enlargement of the thyroid gland was apparently recognized by the Chinese at least as early as 1500 B.c. Such is indicated by drawings and other historical records. Indeed, the people used to overcome the condition in the Middle Ages by eating burnt sponge and seaweed which are rich in iodine. Not until 1916, however, was the evidence accumulated that made it certain that small doses of iodine taken frequently by the patient living in areas in which there are small amounts of iodine in the soil and in the water will prevent simple goiter.
Certain substances have been recognized as having the power to stimulate goiter, but goiter caused by these substances-like thiocyanates or cabbage, which cause a lessening of thyroid hormone-is infrequent.
The chief symptoms of goiter are, of course, the enlargement and bulging in the throat due to the large size of the gland. There are cases, however, in which the enlargement becomes so great that it may even interfere with breathing or injure the voice by pressure on the nerves that go to the larynx. The prevention of such enlargement of the gland by the taking of small doses of iodine regularly during the period of childhood and adolescence is now well established. Iodized salt is now commonly used, so that the iodine is taken regularly in this manner. In cases of severe enlargement of the gland obviously removal by surgery is desirable.