Tetanus (lockjaw) is a preventable but dangerous bacterial infection that causes muscle spasms, trouble opening the mouth (lockjaw), trouble swallowing, and seizures. Usually found in dirt and soil, tetanus bacteria typically enter the body through a wound or cut.

Tetanus bacteria thrive only in the absence of oxygen. The deeper and narrower the wound, the less oxygen is around it, and the greater the possibility of tetanus. For example, tetanus bacteria can thrive in a puncture wound from a dirty nail.

Following the recommended immunization schedule helps prevent tetanus. Before age 6, children receive a series of tetanus shots (DTaP). Then, teens and adults get regular tetanus booster shots.

A person who has a dirty cut or wound should get a tetanus shot as soon as possible if at least 5 years have passed since his or her last tetanus immunization.