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 ...

Though many people experience muscle twitching, it's often incorrectly identified as a muscle spasm. While both are involuntary contractions of a muscle, muscle spasms and muscle twitching aren't ...

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When you buy through links on our articles, Future and its syndication partners may earn a commission. Credit: Getty Images It tends to happen when you’re just about to drift off where your legs or ...

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 ...

At one point or another, we’ve all experienced the unexpected, intense pain of a muscle cramp. Muscle cramps, also known as muscle spasms or charley horses, are the involuntary contraction of muscle ...

Stiff person syndrome (SPS) causes you to have muscle stiffness and spasms, often triggered by sudden noises or touch. You can use medications like muscle relaxants and anticonvulsants to relieve ...

In the realm of bodily quirks, few experiences are as disconcerting and curious as the sensation of your eye jumping or twitching. This phenomenon, medically referred to as myokymia, is commonly ...

Twitching at night—it’s something few of us talk about, yet it’s also a phenomenon that impacts Americans when it comes to sleep quality. And even if you feel like you’re getting enough sleep, you ...