In recent years, the incidence of thyroid tumor has increased significantly, especially in coastal areas, the incidence ranking has increased 4 to 5 places compared with 10 years ago, and the number of incidence is 4 times of that 10 years ago. The thyroid gland is in the front of the neck, below the laryngeal nodes and on both sides of the trachea. It is an endocrine organ in the human body, which undertakes the functions of iodine intake and storage, synthesis and secretion of thyroxine. The normal thyroid gland is thin and soft, and cannot be seen or felt. If the lump is not painful and isolated, the possibility of thyroid cancer cannot be ruled out. Even if a lump appears, it is often mistaken for other diseases and treatment is delayed. The average duration of the disease from the discovery of the lump to the consultation is 5 to 6 years, some even up to 30 years, which delays the best time for treatment. Thyroid cancer is a malignant tumor and if not detected early, it will be a time bomb buried in the neck and will endanger the life of the patient. The age of onset of thyroid cancer is mainly young adults between 20 and 40 years old, more women than men, and the incidence rate is about three times that of men. In addition to the fact that thyroid cancer is a hormone-dependent tumor, women in this age group are prone to develop the disease because of the high secretion of estrogen and progesterone, and it is also related to white-collar women’s competition in the workplace, life pressure and environmental pollution. Young women with emotional instability, mental stress, late childbirth and abortion lead to endocrine disorders and are vulnerable to cancer cells. Self-examination of thyroid gland In order to resist the attack of thyroid tumor, young women should learn self-examination of thyroid gland by lightly pressing both sides of the trachea in front of the neck with fingers through the mirror and pay attention to the following conditions of the thyroid gland: 1. The shape of the lump. The shape of the enlarged thyroid gland is generally divided into two categories, one is butterfly-shaped, mostly seen in patients with thyroiditis and some hyperthyroidism; the lumps are diffusely enlarged or multi-nodular enlargement, mostly endemic goiter. Another type of mass is a round mass in a certain part of the thyroid gland, mostly seen in thyroid cysts, thyroid adenomas, nodular goiters, and also thyroid cancer. 2. The size of the lump. Generally, the diameter of a single nodule of benign tumor or cyst is mostly around 2 cm; if the diameter exceeds 2 cm, thyroid cancer should be suspected. 3. Smoothness and softness of the lump. If a single nodule is enlarged but has a smooth and uniform surface, it may be an adenoma; if a single nodule is enlarged, does not behave smoothly and has a solid feeling, cancer should be suspected. 4. Growth rate of the lump. Benign tumors and cysts grow slowly, and the course of the disease can last from several months to several years; while the lump of thyroid cancer grows rapidly, and the swelling is obvious within ten days or one or two months. 5. Whether lymph nodes are palpable around the lump. If hard lymph nodes can be touched around the thyroid gland, it should be highly suspected that the thyroid cancer is accompanied by local lymph node metastasis, and you should consult a doctor quickly. In advanced stage of thyroid cancer, metastasis of cervical lymph nodes, rapid enlargement of tumor, compression of trachea, infiltration of esophagus and laryngeal nerve, and complications such as difficulty in breathing, hoarseness and obstruction when swallowing food may occur; in severe cases, lung metastasis and bone metastasis may also occur. Thyroid cancer and iodized salt Prevention of thyroid cancer is not simply iodine supplementation. Because, too much iodine intake can also lead to thyroid cancer. There is a specific dose-response relationship (Benrand curve) for any nutrient, i.e., appropriate intake can maintain health, while too low or too high intake can lead to deficiency, poisoning or death; the same is true for iodine. In iodine deficient areas, once the iodine intake is tested to be too high, one should not overdo it by choosing non-iodized salt, but by mixing iodized salt and non-iodized salt. Since potassium iodate, which has very low volatility, is added to iodized salt, it is not possible to effectively reduce iodine intake through high temperature cooking or sunlight exposure. Therefore, the need for iodine-free salt should be determined by iodine intake testing under the guidance of a specialist. In addition, the occurrence of thyroid cancer is the result of a combination of pathogenic factors, which may be related to soil, genetic factors, and radiation exposure. Therefore, one should avoid head and neck X-ray irradiation; avoid estrogen; and avoid fatty and spicy foods in life. In conclusion, if we raise our vigilance, detect the pre-cervical swelling early, go to hospital as soon as possible and get standardized treatment, the 10-year survival rate of thyroid cancer patients can reach over 90%.