Though many people experience muscle twitching, it's often incorrectly identified as a muscle spasm. While both are involuntary contractions of a muscle, muscle spasms and muscle twitching aren't ...

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

ATLANTA -- Scientists have linked certain genes to restless legs syndrome, suggesting the twitching condition described as "jimmy legs" in a "Seinfeld" episode is biologically based and not an ...