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, ...

Medically reviewed by Nicholas R. Metrus, MDMedically reviewed by Nicholas R. Metrus, MD Almost all of us will have experienced a fasciculation at one time or another. A fasciculation is simply a ...

Sometimes, people experience random muscle twitches that interrupt their normal daily activities. This is usually not harmful, but can produce discomfort. These random muscle twitches, known as ...

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 ...

Doctors identify these movements as 'fasciculations', because they occur when individual nerve fibers, which control small muscle groups activate independently to produce brief muscle contractions.