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 ...

Every once in a while, your muscles go rogue on you. Whether it’s your eyelid twitching, an involuntary shudder, or a muscle elsewhere contracting at random, twitchy muscles happen to everyone. But ...

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 ...

Why are we asking for donations? Why are we asking for donations? This site is free thanks to our community of supporters. Voluntary donations from readers like you keep our news accessible for ...

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 ...