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, ...

It has happened to many of us. While in the middle of work, a study session or just spending time with friends, your eyelid flutters for no apparent reason. At first, it may be nothing more than a ...

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 ...

Add Yahoo as a preferred source to see more of our stories on Google. Though eyelid twitching (technically called myokymia) can feel disconcerting, the good news is that it’s typically fleeting and ...