The sequelae after thyroid cancer removal mainly include these aspects: firstly, hypothyroidism after complete thyroid gland removal, which may manifest as slow reaction, poor appetite, and edema of limbs; secondly, hoarseness after damage to the laryngeal return and superior laryngeal nerve, and choking and coughing when drinking water or choking if it is severe; thirdly, parathyroid gland injury by mistake, especially when all parathyroid glands are removed. Thirdly, the parathyroid glands are accidentally injured, especially after all the parathyroid glands are removed, resulting in hypocalcemic convulsions caused by the reduction or even disappearance of parathyroid hormone, which can be manifested as paroxysmal twitching of the limbs, and blood tests often show hypocalcemia. There are other localized conditions such as scarring and localized recurrence of thyroid cancer, but these are rare.