General anesthesia is the safest and most comfortable anesthesia for patients. In developed countries, more than 90% of operations are performed under general anesthesia. Intubation is to facilitate the management of respiratory tract, and insert trachea or laryngeal mask through mouth. General anesthesia drugs take effect quickly and are eliminated quickly. Generally, patients will lose consciousness for more than ten seconds after taking drugs, so patients can't feel these operations, just like sleeping, and of course they won't hurt. General anesthesia is very controllable, so it is safe. Unless there are complications in some cases, there are generally no sequelae.