The symptoms of distant metastasis of thyroid cancer depend on the specific location to which the tumor has metastasized, and the specific symptoms are as follows: 1. lung metastasis: there may not be any clinical symptoms; if the lung metastasis is close to the location of pleura, the patient may show symptoms of irritating cough; 2. liver metastasis: there may be loss of appetite, inability to eat greasy things, and liver function damage; 3. bone metastasis: there may be pain in the corresponding area; 4. brain metastasis: there may 4. Brain metastasis: dizziness, headache, vomiting, loss of vision, hearing loss, unstable walking and other characteristic central nervous manifestations may appear. In conclusion, the symptoms of distant metastasis of thyroid cancer need to be judged according to the specific metastatic site and the possible clinical manifestations.