Goiter is a common thyroid disorder. Many people, due to a lack of knowledge about goiter prevention, should change their diet by not eating or eating less of these foods if they eat large amounts of cabbage, cabbage, greens, cassava, walnuts, soy foods, and radishes over a long period of time. If the thyroid gland becomes smaller or the goiter disappears, it means that the goiter is related to this kind of diet. Eat a little more iodine-rich food in the diet as appropriate, observe for a period of time, and thereafter if the goiter shrinks, it means that this measure is effective. If the goiter is enlarged and does not shrink, other methods should be considered, and it is best to go to the hospital for medical advice.