Post-thyroidectomy drains are usually left in place for 2 to 3 days, which can be extended to a week depending on the situation when there is a lot of drainage fluid. The time of placing the drain after thyroidectomy is mainly based on the amount of drainage fluid after the surgery. When more exudate accumulates, it can compress the trachea, esophagus or arteries, etc., which can be life-threatening in severe cases. Therefore, it is necessary to leave a drain to drain the exudate after surgery to relieve the pressure symptoms and reduce the chance of infection. After thyroidectomy, the exudate is usually small and can be drained for 2~3 days. When the hemostasis after thyroidectomy is not sufficient, due to the microvascular damage exudation, the exudate will persist, but the damaged microvessels usually close completely in about a week, so when the drainage fluid is more, it can be extended to one week according to the situation.