I cut my finger on a can lid, what are the signs of lockjaw and how long should I worry?

"lockjaw" When did you last have a tetanus (lockjaw) booster? If more than 10 years or the wound was contaminated (dirt, etc), see your doc or county health dept for update. Signs of tetanus are marked muscle spasm of all muscles. Best to be immunized rather than wait for symptoms to occur. Now recommended that the booster also cover diphtheria and pertussis (tdap). If in doubt, get the booster.