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 ...

Hemifacial spasm (HFS) is a rare movement disorder that causes involuntary muscle contractions on one side of the face. It typically starts with painless but annoying twitching around one eye. Over ...

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, ...