Anesthesia is a general term for medication used to dull or numb pain during a procedure or surgery, or to reduce nerve pain in patients with certain conditions. General anesthetics may be used during surgical procedures to make patients completely unconscious and unable to feel pain while local anesthetics numb a localized area while patients retain consciousness. Anesthetics have a variety of routes of administration, for example, they may be administered as an injection, topical, inhaled, oral or rectal.

A huge variety of anesthetics are available to physicians, but some commonly used varieties include neuropathic pain and peripheral neuropathy agents, ophthalmological local anesthetics, topical local anesthetics, and other agents for local oral treatment.