According to Chinese medicine, this disease is mostly caused by inappropriate living in water and soil, or internal injury from the seven emotions, or dietary disorders, or inadequate endowment X. As a result, qi stagnation, phlegm condensation, blood stasis and congestion in the front of the neck, gradually enlarging or forming lumps. Modern medicine believes that the main causes are congenital genetics, depression, viral infections, etc., resulting in iodine deficiency, simple goiter, hyperthyroidism, thyroid tumors, and chronic lymphocytic thyroiditis. In the past and present, some doctors have often used kelp, seaweed, kombu, sea pumice, cuttlebone and other iodine-rich herbs for the treatment of these diseases, such as the treatment of qi and phlegm, dispersing knots and eliminating galls. Modern pharmacological research has confirmed that the main ingredients of kelp, seaweed and kombu are iodine, and the iodine content of kelp is the highest, followed by seaweed and kombu, which fully explains the treatment of thyroid disease with seafood drugs such as kelp. There is a safe range for all the essential trace elements in the human body, the lack of which can lead to elemental deficiency, and the excess of which can lead to poisoning and adverse consequences. In clinical applications, it is not difficult to find that the above-mentioned iodine-rich drugs used for thyroid disease sometimes do not work well, and even the worse the treatment, the worse the condition. What is the reason for this? This is mainly due to the unclear understanding of the cause and the unclear identification of the evidence when using drugs. Clinical practice has confirmed that the use of such drugs to treat thyroid disease should master three principles: First, forbidden to high iodine goiter. The first thing you need to do is to take a look at the actual results. In 1979-1980, Hebei Province first reported that high iodine goiter was caused by drinking water from deep wells in Bohai Bay. Later, it was found that water source hyperiodothyroidism was also found in the coastal areas of Bohai Bay in Shandong Province. In addition to water source hyperiodothyroidism, there are also food hyperiodothyroidism caused by the consumption of iodized salt, iodized bread and high iodine food, or improper medication in the prevention and treatment of iodine-deficient endemic goiter, which can cause drug hyperiodothyroidism. Although most of the goiters seen in clinical practice today are caused by iodine deficiency, there are some that are caused by high iodine. The clinical manifestations of hyperiodized goiter are basically similar to those of iodine-deficient goiter, except that it is slightly hard and solid when palpated. The laboratory tests show a significant increase in urinary iodine, up to 1000 μg/day or more, and the rate of iodine uptake by the thyroid gland is very low. The more iodine-containing drugs (or diet) a goiter takes, the larger the swelling becomes, so iodine-containing drugs or a diet high in iodine must be banned during or after treatment. Second, use with caution in hyperthyroidism. Hyperthyroidism is a disease caused by a pathological overproduction of thyroxine by the thyroid gland and increased metabolism in the body. Although iodine can inhibit the release of thyroxine, it cannot inhibit the synthesis of thyroxine. If iodine is used for a long time, it is not good for hyperthyroidism, so it should be used with clinical caution. From the point of view of Chinese medicine, hyperthyroidism is mostly manifested as hyperactive liver fire or deficiency of both qi and yin, and treatment focuses on nourishing yin and lowering fire. At this time, if you use drugs to eliminate galls and disperse knots, you should be careful with salty and cold products such as seaweed and kombu. Third, pregnant women should be careful with iodine supplementation. Excessive iodine supplementation in pregnant women can suppress their own thyroid function and may also directly damage the thyroid function of the fetus and newborn. In the literature, it is reported that 17.6% of infants with skin contact with iodine can cause transient hypothyroidism due to the extreme fragility of fetal and neonatal tissues. The explanation that maternal high iodine can cause fetal hypothyroidism or goiter is contained in classical medical texts. The inhibitory effect of high maternal iodine on fetal thyroid synthesis is medically known as the “Vorbunov-Tchaikov effect”. Therefore, many domestic and foreign medical experts advocate the need for iodine supplementation in pregnant women and newborns, but caution must be exercised when giving iodine-containing drugs to pregnant women and newborns.