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

‌Hemifacial spasm is a disorder of the nerves and muscles that causes nonpainful involuntary twitching on one side of the face. Many people refer to hemifacial spasms as lip muscle spasms. Hemifacial ...

Many of us have felt a muscle in some part of our body suddenly and involuntarily tighten, causing a twitch or even severe cramp. Muscle spasms are common and typically don't signal a severe health ...

Most people have likely had the unpleasant experience of a muscle cramp, also known as a charley horse or muscle spasm. And while most cramps will quickly go away on their own, there are a few helpful ...

Muscle spasms are the sudden, intense and uncontrollable contraction of muscles. They're painful and frustrating, and can stop athletes in their tracks or jolt someone awake in the middle of the night ...

You're in the middle of your squat reps — weight in hand — and just like that, a charley horse causes your calf muscle to go rogue. When this type of muscle spasm or cramp hits, there is no mistaking ...

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.