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Local anesthesia uses medicine 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 medicines that make you relaxed or sleepy (sedatives). These other medicines are often given by IV.

Local anesthesia is most often used when:

• A minor procedure doesn't require general or regional anesthesia.
• A surgery can be done in a short time and you will go home soon after.
• A surgery does not require unconsciousness or extreme muscle relaxation.

Less commonly, local anesthesia may be applied directly to the skin or mucous membranes as a cream or ointment. This is called topical anesthesia. Topical local anesthesia is used for very minor procedures on the surface of the skin.

Risks and complications from local anesthesia

When used properly, local anesthetics are safe and have few major side effects. But in high doses, local anesthetics can have toxic effects caused by being absorbed through the bloodstream into the rest of the body (systemic toxicity). This may significantly affect your breathing, heartbeat, blood pressure, and other body functions. Because of these potential toxic effects, equipment for emergency care must be immediately available when local anesthetics are used.