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 relaxing on the sofa when suddenly your eyelid starts twitching. Or perhaps it's a muscle in your arm, your leg, or your foot that begins to ...

Medically reviewed by Amy Kwan, PT Lower right back pain can come from issues with muscles, discs, joints, or internal organs.  Numbness, tingling, or weakness with lower right back pain is often a ...