Medically reviewed by Arno Kroner, DAOM Key Takeaways Hypnic jerks are common, sudden muscle twitches that happen when you fall asleep.Stress, anxiety, and fatigue can increase the chances of ...

Though many people experience muscle twitching, it's often incorrectly identified as a muscle spasm. While both are involuntary contractions of a muscle, muscle spasms and muscle twitching aren't ...