Anesthesia is broken down into three main categories: local, regional, and general, all of which affect the nervous system and are administered using various methods and medications.
• Local anesthesia. An anesthetic drug (which can be given as an injection, spray, or ointment) numbs only a small, specific area of the body (for example, a foot, hand, or patch of skin). With local anesthesia, a person is awake or sedated, depending on what is needed. Local anesthesia lasts for a short period of time. It is often used for minor outpatient procedures (when patients come in for surgery and can go home that same day). For someone having outpatient surgery in a clinic or doctor's office (such as the dentist or dermatologist), this is probably the type of anesthetic used. The medicine used can numb the area during the procedure and for a short time afterwards to help control post-surgery discomfort.
• Regional anesthesia. An anesthetic drug is injected near a cluster of nerves, numbing a larger area of the body (such as below the waist, like epidurals given to women in labor). Regional anesthesia is generally used to make a person more comfortable during and after a surgical procedure. Regional and general anesthesia can be often combined.• General anesthesia. The goal is to make and keep a person completely unconscious with no awareness or sensations during surgery. General anesthesia can be given through an IV (which requires sticking a needle into a vein, usually in the arm) or by inhaling gases or vapors through a mask.