What Causes Muscle Twitches, According to Science

Sometimes, it seems like muscles have a mind of their own. Whether it’s a twitchy eyelid, a sudden spasm in your thigh or a muscle that seems to contract without cause, involuntary muscle movements are exceedingly common. (One might even be happening to you, right now, as you read this sentence.) Most muscle twitches fall under the category of fasciculations —small, involuntary movements that can occur at random to any muscle in the body, although they’re most common in the eye