Medications which block pain and other sensations, sometimes rendering the patient unconscious, for the performance of surgical procedures. Levels of anesthesia can be general, regional or local. General anesthetic puts a patient to sleep. Local anesthetic causes loss of feeling in a part of the body such as a a tooth or an area of skin without affecting consciousness. Regional anesthetic numbs a larger part of the body with affecting consciousness. Conduction anesthetic (often used in procedures such as a C-Section) encompasses both local and regional anesthetic techniques, allowing surgical procedures to be done without significant pain. Also spelled anaesthesia.