Adrenaline increases the "alertness" of the nervous system, meaning it's ready to trigger muscle contraction. It also increases the amount of blood flow and changes the tension of the muscles, which, ...

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 ...

If you’ve ever developed an eye twitch, you’ll know how disconcerting it can be. But thankfully, according to ophthalmologists, that irritation is likely nothing to worry about. “The medical word for ...