hi crystalrose, the best explanation I have found that describes them in depth and easy to understand was on wiki but it has change a bit since I last read it.

http://en.wikipedia.org/wiki/Hypnagogia

There are more links at the bottom of the page, some of which are good too. Mine are alway accompanied with auditory, visual, tactile and sleep paralysis. It's rather unpleasant and too long for me to explain properly. When I was younger I thought I was being attacked/haunted by the paranormal upon falling asleep and waking up. Having sleep paralysis while your nightmare enters the room with you as you wake up is awful, so is the feeling of being touched, grabbed, slapped or pinned to the bed with the feeling of a heavy nasty presence in the room. W

I was just wondering if anyone else out there has suffered or is suffering from them too. W