Medically reviewed by Jennifer Steinhoff, MD Key Takeaways Muscle twitching is often caused by stress or a lack of sleep and ...

You’re sitting at your computer when it starts — that annoying flutter in your eyelid that feels like a tiny butterfly trapped under your skin. Most of the time, eye twitching is harmless and goes ...

Medically reviewed by Nicholas R. Metrus, MD Key Takeaways Too much caffeine can cause lip twitching, and cutting back on ...

Do your muscles still spasm after a run? This is most likely muscle fasciculation, where the voluntary muscle units are randomly firing and not under the usual central nervous system neurologic ...

Whenever I run, whether five miles or 20 miles, my calf muscles are twitching/spazzing when I'm finished. They do not seize and cramp, but it's like they're firing all over, uncontrollably. This ...