Recently, several patients were admitted to the clinic who presented with paralysis of one vocal cord due to thyroid cancer that was not treated early. The results of treatment for these patients were not very satisfactory. The reasons for this are as follows: 1. Because the cancer does not affect eating and breathing, it is not treated for a long time, causing the tumor to become larger or even malignant and eventually invade the laryngeal nerve, esophagus or trachea wall. 2.Distant metastasis was already present at the time of consultation. 3.The cancer cells are low differentiated carcinoma, which progresses rapidly and develops fast. The manifestation of invasion will appear soon, such as invasion of the recurrent laryngeal nerve, esophagus, tracheal wall, etc. The consequences: (1) The risk of surgery increases. Because of the large tumor, or adhesions with peripheral nerves and blood vessels, the chance of postoperative complications, such as hemorrhage, hypocalcemic convulsions, etc., is increased. (2) Extensive tumor invasion leads to tumor not easily removed cleanly and easy to recur. (3) Quality of life is reduced. (1) Some of them need tracheotomy or even long-term tube wearing, which requires suction, drug change, cleaning, etc. ②Some need long-term gastric tube nasal feeding diet. ③Part of them need to have laryngectomy and lose vocal function. Therefore, thyroid cancer must be diagnosed and treated as early as possible.