Recently, the Beijing Municipal Health and Population Health Status Report 2013 (Health White Paper) released by the Beijing Municipal Health and Family Planning Commission shows that among the new cases of malignant tumors, the incidence of thyroid cancer is 15.74/100,000, up 393.42% from 2003 (3.19/100,000), with an average annual increase of 16.92% after age standardization, indicating that thyroid cancer has become the The average annual increase is 16.92% after age standardization, indicating that thyroid cancer has become the fastest growing malignant tumor in Beijing. The increase rate of nearly 400% is alarming, and thyroid cancer is raging. I. Definition: What is thyroid cancer? Thyroid cancer accounts for 1% of all malignant tumors in the body. Except for medullary carcinoma, most thyroid cancers originate from follicular epithelial cells, and most of them are papillary carcinomas. The incidence of thyroid cancer is related to region, race and gender. Second, the causes of high incidence of thyroid cancer worldwide have been analyzed by a large number of epidemiological surveys, and the following factors have been internationally agreed upon, but further research is needed. 1. Diagnostic techniques and thyroid screening are important reasons for the high incidence of thyroid cancer, but they are not the only factors. With the development of medical diagnostic technology and socio-economic development, the rate of medical consultation and disease screening among the population has increased, and the detection rate of early stage disease has been improved. For example, in the past, thyroid cancer may have to grow to 1 cm in diameter before doctors can detect it by touch; however, with the widespread use of ultrasound diagnostic technology, B can be detected even at 0.1 cm in diameter. Data from the Yale School of Public Health, Division of Environmental Health and School of Medicine, Department of Surgery, published in 2014, showed that the incidence of thyroid cancer increased significantly in all states of the United States. There were significant geographic differences in incidence rates: highest in the Northeast and lowest in the South. Incidence rates were significantly associated with endocrine/surgeon density and significantly associated with the use of neck ultrasound. Endocrine/surgeon density and use of ultrasound density explained the interstate variation in nail cancer. CONCLUSION: The evidence suggests that the high incidence of thyroid cancer is due to increased screening for a “reservoir of hidden disease. Therapeutic interventions (including surgery and radiation therapy) triggered by increased screening have had limited benefit. Current trends in the growth of thyroid cancer, as reported by the New York Cancer Center and others in 2013, suggest that more occult cancers will be detected and thus treated with interventions that may not be beneficial for patients with this potentially harmful cancer only. The overdiagnosis of thyroid cancer increases the concern in the public health field. 2. Environmental factors are another important factor. (1) Exposure to radiation during childhood. This is now a recognized risk factor worldwide because the thyroid gland is extremely sensitive to ionizing radiation during childhood. 2013 published a collaborative investigation between the United States and Japan investigated the incidence of thyroid cancer in survivors 60 years after the atomic bombing in Japan, and the results showed that the risk of developing thyroid cancer in children exposed to radiation can last for more than 50 years, and the younger the child is when exposed to radiation, the higher the risk of developing thyroid cancer. 2014 A survey led by the Chinese Center for Disease Control and Prevention investigated the CT scans received by children in a municipal hospital in Ningbo, China, for the whole year of 2012, and assessed the risk of thyroid cancer in these children based on a model designed in the United States for calculating the risk of cancer caused by ionizing radiation, and found that 1,307 children aged 0-15 years in this hospital received CT scans in the whole year of 2012, of which the thyroid gland could be exposed to The CT scans (including sinus, head, and chest) accounted for 74.3% of the total CT scans, with the chest CT having the highest radiation exposure to the thyroid. An assessment of the risk of thyroid cancer in these children showed that the rate of possible thyroid cancer after chest CT in girls was 14.1/100,000, head CT was 8.7/100,000, and sinus CT was 2.7/100,000, and the risk was higher at younger ages. These results deserve the attention of doctors and parents, and are one of the core elements of our health education. (2) Exposure to harmful chemicals. These substances are widely found in soil, drinking water, certain vegetables and grains. They can compete with iodine and affect the uptake of iodine by the thyroid gland, so they have a greater effect on those who are iodine deficient and a smaller effect on those who have sufficient iodine. ②Carcinogenic substances: bromides, formaldehyde, nitrites, polycyclic aromatic hydrocarbons, volcanic ash, etc., which have been proved to be obviously carcinogenic. 3. Dietary factors. (1) Iodine intake. Since iodine has a double-edged sword effect on the thyroid gland, iodine deficiency or excess iodine can affect the thyroid gland, so residents should maintain an adequate and appropriate level of iodine intake. (2) Diet or lifestyle. It has been proved that metabolic disorders caused by obesity can increase the risk of thyroid cancer. 3. Suggestions: How to prevent thyroid cancer? 1.Avoid ionizing radiation: Reduce or avoid radiation especially during childhood (focus on radiation of medical origin). 2. Avoid iodine deficiency or iodine overdose. 3.Control weight and reduce obesity. 4.Choose a variety of foods and increase the consumption of fresh fruits and vegetables.