That sudden jolt or twitch just as you’re drifting into sleep isn’t your imagination. It’s a real physiological event. One moment, you’re fading into slumber, and the next, your arm or leg flings out ...

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 ...