The thyroid gland is a small butterfly-shaped organ located in our neck, but it is the main regulator of the body’s metabolism and the engine of the body. The thyroid gland regulates the normal functioning of the body’s tissues and organs by producing, storing and releasing thyroxine into the bloodstream. However, in recent years, the incidence of thyroid disease has increased significantly, especially in coastal areas, and thyroid nodules have become common in the general population. Many people who suffer from thyroid nodules may ask: Why do thyroid nodules grow on the thyroid gland? How is it related to iodine? Then let us answer these questions. The causes of thyroid nodules are not the same. Clinically, there are many thyroid disorders such as degenerative thyroid, hyperthyroidism, inflammatory thyroid, autoimmune diseases, as well as thyroid adenomas, nodular goiter and thyroid cancer, which can manifest as multiple or single nodules on the thyroid gland. Thyroid nodules are more common in middle-aged women, and although most patients have benign nodules, the proportion of malignant nodules is increasing each year. In particular, solitary thyroid nodules in young and middle-aged men need to be taken more seriously. The body needs iodine to produce thyroxine and to maintain normal physiological functions. Iodine is mainly obtained from food, but in iodine-deficient areas the iodine content in water and soil is very low, so the iodine content in food harvested, animals and plants grown in this environment is also very low. Regular consumption of these foods can lead to iodine deficiency, and these iodine deficient areas are mainly located in mountainous regions. Iodine deficiency can lead to “big neck disease”, hypothyroidism, and even mental retardation. For this reason, our government has adopted the international practice of adding iodine to table salt. If a normal person consumes less than 50 micrograms of iodine per day, he or she may suffer from iodine deficiency and needs to increase the supply of iodine. If you can get more than 100 micrograms of iodine per day from outside sources, you will have enough to meet your body’s needs. However, too much iodine can also be detrimental to health. Patients in adolescent physiological hyperthyroidism can eat more seaweed, kelp and other seafood to meet the body’s needs. However, if a patient with hyperthyroidism does not consult a doctor in time, but eats iodine-rich foods on his own, he may delay his condition and lead to thyroid crisis or even endanger his life. Although iodine deficiency can cause thyroid nodules or goiter, excessive iodine consumption over a long period of time can also cause thyroid nodules to develop and even increase the chance of thyroid cancer. The consumption of iodized salt in iodine-deficient areas remains the most important initiative to eliminate iodine deficiency disorders. Coastal residents, especially those who regularly eat iodine-rich seafood such as seaweed and nori, can reduce their intake of iodized salt. Those who have a family history of hyperthyroidism or thyroid cancer are better off with a low iodine diet. Of course, don’t be afraid of iodized salt, as it is not harmful to our health as long as it is consumed properly. If you find a thyroid nodule, please do not blindly increase or stop iodine, but go to the hospital. A professional doctor can determine the size and nature of the thyroid mass through TSH measurement, thyroid function, thyroid ultrasound, fine needle aspiration biopsy and radionuclide scan. However, if ultrasound shows that the nodule is a substantial mass, punctate microcalcifications, irregular border, abundant blood flow within it, infiltration of surrounding tissues, or with lymph node metastasis, and radionuclide scan shows a cold nodule, then these are indications that you may have thyroid cancer. Thyroid surgery is the main means and effective method to treat thyroid lumps and is especially suitable for patients with suspected thyroid cancer. Early detection, early diagnosis and early treatment bring you a healthy thyroid gland.