This is actually due to the normal edema reaction of the incision after thyroid surgery. Thyroid surgery requires separation of the upper and lower flaps of the incision, which can easily cause edema in the tissues around the incision, especially in middle-aged and elderly women, because the skin is more relaxed and there is more subcutaneous fat, so the incision is more likely to be edematous. Local hot compresses after surgery can accelerate the absorption of edema. Usually the edema will last for about 1-3 months.