After thyroid surgery, patients are required to undergo regular review. The purpose of review is mainly the following two: 1) to understand the functional status of thyroid gland; 2) to understand the recurrence of thyroid tumor after surgery. Basically, patients are required to have a review once in 6 months or so, and the main items to be checked are thyroid function, i.e. T3, T4 and TSH, which are the three common items. Ultrasound is also recommended for patients to observe the morphology of both sides of the residual thyroid gland and to avoid the occurrence of microscopic nodules.