Infectious agents can cause muscle twitching and spasms, too. The most commonly known is probably tetanus, which causes a phenomenon called lockjaw, where the neck and jaw muscles contract to the ...

Night leg cramps, or nocturnal leg cramps, are sudden, involuntary muscle contractions that usually occur in the calves, feet, or thighs during rest or sleep. These painful spasms can last from a few ...

You’re relaxing on the sofa when suddenly your eyelid starts twitching. Or perhaps it’s a muscle in your arm, your leg, or ...