Cataplexy is a sudden, brief loss of voluntary muscle tone triggered by strong emotions such as laughter, excitement, anger or fear. There is a strong association between cataplexy and narcolepsy, a ...

And not figuratively, either. Sometimes people have found that certain emotions literally cause their muscles to unhook from their brains. They collapse entirely. This is not some strange disease, or ...

Cataplexy, or sudden muscle weakness that can resemble fainting, may be prompted by strong emotions. This symptom isn't serious and mostly occurs with narcolepsy type one — otherwise, it's very rare.