Whether or not a urinary catheter is inserted for thyroid surgery depends largely on the length of the surgery; it is not needed for short periods of time and is needed for long periods of time. The purpose of inserting a urinary catheter for surgery is to prevent the patient from being in surgery for too long, which can lead to urinary retention, and if urinary retention occurs during surgery it may lead to interruption of the surgery. Typical thyroid surgery is relatively simple, simple total or partial thyroidectomy, and is short, most ending in less than an hour, so a catheter is not necessary. If the operation is too long or too complicated, a catheter is needed; if the patient’s own condition, such as advanced age, need for fluids, blood transfusion, etc., a catheter is also needed to be inserted.