Anesthetic drugs are given before a surgical procedure to lessen or stop the pain in part or all of the body.
General anesthesia puts the whole patient into a type of deep sleep.
It is usual to start with an injection of a medication to induce sleep and then follow with anesthetic gases and oxygen to continue the process. A tube will be placed in the mouth to help the patient breathe. For some operations, muscle relaxants will be used to keep the patient from moving during surgery. After surgery, anesthesia is stopped. Short acting drugs simply wear off.