You're relaxing on the sofa when suddenly your eyelid starts twitching. Or perhaps it's a muscle in your arm, your leg, or ...

A muscle cramp is an unexpected tightening or contraction of one or more muscles in the body. These involuntary episodes can be quite painful as the muscle contracts and is unable to relax. They may ...

Muscle fatigue is a decreased ability to create force with your muscles. Electrolyte imbalance and overuse are some of the most common causes of muscle fatigue. Rest and massage are the best ways to ...

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 ...