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

Doctors identify these movements as 'fasciculations', because they occur when individual nerve fibers, which control small muscle groups activate independently to produce brief muscle contractions.

Medically reviewed by Nicholas R. Metrus, MDMedically reviewed by Nicholas R. Metrus, MD Almost all of us will have experienced a fasciculation at one time or another. A fasciculation is simply a ...