Tetanus (from ancient Greek "tetanos" or "taut" and "teinein" or "to stretch", is a disease that causes sustained skeletal muscle fiber contraction, including lockjaw (an uncontrollable tightening of the jaw muscles). Tetanus is caused by a neurological toxin (tetanospasmin) that is produced by bacteria, which infect people (and other animals) through cuts and other wounds to the skin. The bacteria infects the wound and produces this toxin, which causes the muscle contractions. You can be immunized against tetanus, or take medication after being exposed to treat it.