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

Spastic hemiplegia is the most common type of cerebral palsy. This causes symptoms in one-half of their body — you might experience pain, muscle stiffness, and lack of muscle control. Share on ...

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 ...

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 ...