Local anesthesia uses medication to block sensations of pain from a specific area of the body. Local anesthetics are usually given by injection into the body area that needs to be anesthetized. They are not injected into the bloodstream (intravenous, IV).
Local anesthetics may be given with other medications that make you relaxed or sleepy (sedatives). These other medications are often given by IV.
Local anesthesia is most often used when:
Less commonly, local anesthesia may be applied directly to the skin or mucous membranes as a cream or ointment, such as an EMLA cream. This is called topical anesthesia. Topical local anesthesia is used for very minor procedures on the surface of the skin.
WebMD Medical Reference from Healthwise