Local anesthesia uses medicine to block pain from a part of the body. The medicine affects only the area near where the medicine was injected or applied.

How it's done

The medicines are often injected into the area that needs to be numbed. But they may also be put on the skin or mucus membranes as a liquid or gel. Or they may be given as eyedrops.

Risks

Serious problems, including allergic reactions, are very rare. But if the medicine is given in higher doses or if it enters the blood and moves through the body, there can be some side effects. Examples include ringing in the ears, dizziness, and a metal taste in the mouth.