A muscle spasm — also known as a charley horse, muscle cramp or twitch — is a sudden, involuntary movement in one or more muscles. Common causes include stress, exercise, or dehydration, but nerve ...

Dehydration may be one cause of muscle cramps, and some evidence suggests that electrolyte imbalances also contribute to them. Muscle cramps are painful, involuntary contractions of the muscles that ...

Heat cramps are painful muscle spasms that occur due to exercise in hot and humid conditions. While heat cramps aren't dangerous, they can be a sign of heat exhaustion or heat stroke. To avoid heat ...