Many things can cause your thumb to twitch, from lack of sleep to autoimmune conditions. If it continues for more than a few days or occurs with other symptoms, you may need medical care. Thumb ...

While sitting still at your desk or watching TV, you sense a feeling of muscular discomfort in your arm or leg. It’s not quite a charley horse, but you can see your skin pulsating involuntarily, as if ...

Tweaked by a muscle twitch? From an uncontrollable fluttering eyelid to a pulsing calf muscle, these small, rapid involuntary muscle contractions may happen at any time — and can be annoying. A common ...

Benign fasciculation syndrome is persistent twitching in one or more muscles. A person may also experience tingling or numbness. Benign fasciculation syndrome (BFS) is rare and can be confused with ...

Myoclonus (pronounced "my-OCK-lo-nus") is a sudden muscle spasm that you can’t control. It can be a natural reflex – like jumping when something scares you or getting the hiccups from laughing too ...

You’ve probably experienced the uncomfortable feeling when your hand muscles tighten or contract uncontrollably and won’t relax no matter what you do. It happens unexpectedly — when you’re writing ...