I have read in places about people shaking and moving around uncontrollably while sleeping (Such as periodic limb movement disorder), but as far as I know, I do not suffer from this.

For the last few years, I have had occasional nights where I cannot get to sleep because of a constant compulsion to shake myself about when I'm in bed. This isn't just a case of uneasiness or irratation, it is involuntary. I simply cannot stop this erratic, sometimes convulsive behaviour.

It goes away after a while if I stand up, turn the light on or go around the house as if it was daytime. It only started happenning after one particular night when I was about 14 (I'm 18 now), when I was sleeping, lying on my back and I got the feeling that I couldn't breathe. I could hear my pulse going quite slowly but loudly, and then I woke up sweating and unable to get back to sleep.