Tetanus is a disease caused by a bacterial infection. The bacteria make a toxin, or poison, that causes severe muscle spasms. Tetanus can be very dangerous, but you can get a shot to prevent it. Tetanus is also called "lockjaw" because muscle spasms in your jaw make it hard to open your mouth. Tetanus also causes seizures and makes it hard for you to swallow or breathe.
In the United States, most people have had shots to prevent tetanus, so the disease is relatively rare. People who have never been immunized or haven't had a booster in the last 10 years are more likely to get tetanus. This includes people who recently moved to the U.S. from countries where tetanus shots are rare.
If you never had tetanus shots as a child, or if you're not sure if you had them, you'll need to get 3 tetanus shots in about a 1-year time span. After that, 1 booster shot every 10 years will work for you.
Get a tetanus shot as soon as possible if you have a dirty cut or wound and 5 or more years have passed since your last tetanus shot. Some people may need tetanus immunoglobulin (TIG) for a wound that is at high risk for tetanus. The immunoglobulin is usually only needed if you have not (or do not know whether you have) completed the tetanus shot series.