Sleep paralysis is something that occurs right before or after you sleep.
What happens is: the only thing you can move is your eyes and you get some severe hallucinations.
The first time it happened to me was the worst. I couldn't move anything, but my eyes were open and I felt a lot of pressure on my chest, it was like someone was standing/ sitting on it. I also felt like there was something evil in the room trying to get me, which was the most terrifying thing ever, after a few seconds I even started hearing footsteps right next to my bed. this all probably lasted a minute (the longest minute of my life), which is a good thing cause just before I snapped out of it I started seeing a shadow.
The second time wasn't as bad as the first one, but still terrifying. I woke up with my arms crossed (even with my 'bionic arm' / wolverine thingy) and felt like my phone was lying on top my left hand, it was ringing. when I tried to pick it up I noticed that I couldn't open my eyes and couldn't move my arms. even though I immediately knew what was going on, I still panicked when I started hearing 2 voices whispering really fast (1 in each ear). in an effort to get someone to snap me out of it I started producing sounds in my mouth (you can't open your mouth). after 3 tries I eventually snapped out of it by myself.
I looked it up and there's so much more that could happen during sleep paralysis, like an out of body experience but I haven't experienced that.
@Sarah, don't worry:
Sleep paralysis poses no serious health risk to those that experience it, despite the fact that it can be an intensely terrifying experience.