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, ...

At first glance, tics and body-focused repetitive behaviors (BFRBs) can look remarkably similar. Both involve repeated behaviors that may seem involuntary, often start in childhood or adolescence, and ...

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 ...

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 ...

Obsessive-compulsive disorder (OCD) is a mental health condition that involves repetitive thoughts and behaviors. If you have OCD, you might also experience tics or disruptive involuntary sounds or ...

ADHD and tics are separate but closely related conditions. About one in five people with ADHD also have a tic disorder. Jump to Key Takeaways. Tics are sudden, repetitive actions that people cannot ...