Anesthesia

Anesthesia (American English), also anaesthesia (British English), is the process of blocking the perception of pain and other sensations. This allows patients to undergo surgery and other procedures without the distress and pain they would otherwise experience. There are several forms of anesthesia:

general anesthesia — with reversible loss of consciousness
local anesthesia — with reversible loss of sensation in a (small) part of the body by localized administration of anesthetic drugs at the affected site.
regional anesthesia — with reversible loss of sensation and possibly movement in a region of the body by selective blockade of sections of the spinal cord or nerves supplying the region.
Physicians specialising in the administration of anesthetics are known as anesthesiologists (AE) or anaesthetists (BE). Nurses specialising in the administration of anesthetics are known as nurse anesthetists (AE), who typically have gone to graduate school after nursing school, or have at least obtained certification as a CRNA (Certified Registered Nurse Anesthetist). "Anesthetist", despite typically (in the USA) referring to nurses, can refer to a physician or a nurse. Anesthesiologist Assistants are another group of health care providers who administer anesthetics. They pursue a graduate degree in anesthesia from an accredited program and are supervised directly by an anesthesiologist.