The exact cause of thyroid cysts is not very clear, but some scholars believe it is related to iodine metabolism. Therefore, in areas where iodine is particularly lacking or particularly abundant, the incidence of thyroid cysts tends to increase. Hence, the diet should avoid both too low and too high iodine intake. As for eating sea fish, occasional consumption should be acceptable. However, eating sea fish daily may lead to excessive iodine intake, potentially causing further development of the cysts.