this happened to me about a month ago. i'm pretty sure it was my first experience and it freaked me out! i felt presure on my chest and i knew or was at least very sure i was awake. had a laugh about it with some friends the following day.

just in addition to peachy say in northern part of phillipines they believed that the cause of sudden death is a fat ugly lady who sit in their chest so they can't breath normally speacially when eat to much. cowboy...

Yes, most folkloric expressions refer to some spirit or creature sitting on or pushing down on your chest. It's the duwende!! ;P I experience hypnagogic paralysis, by the way. The other type is hypnopompic.