Long workdays. Missed meals. Poor sleep. Most people blame these when legs cramp at night or eyelids twitch during meetings.

You're relaxing on the sofa when suddenly your eyelid starts twitching. Or perhaps it's a muscle in your arm, your leg, or your foot that begins to spasm—sometimes for a few seconds, sometimes for ...

While sitting still at your desk or watching TV, you sense a feeling of muscular discomfort in your arm or leg. It’s not quite a charley horse, but you can see your skin pulsating involuntarily, as if ...

Functional tics are dramatic, involuntary movements or sounds usually made in response to a trigger. While similar to other tic disorders, they have different causes and treatment options. Functional ...