Anesthesia is the use of drugs to temporarily eliminate the sensation of pain and is widely used in medicine. Common forms include local, regional, and general anesthesia. Local anesthesia affects a small part of the body. As an example, dentists utilize local anesthesia by injecting the patient's gum with Novacaine. Regional anesthesia affects a larger region of the body. As an example, physicians may apply regional anesthesia to affect a patient's limb. General anesthesia is drug-induced to cause a patient to lose consciousness.
Prior to surgery, general anesthesia is typically induced to patients causing them to lose consciousness so patients are not aroused during operation, even if sharp pain is inflicted. General anesthesia is administered by inhalation.