I've had that too. Sleep Apnea: http://en.wikipedia.org/wiki/Sleep_apnea. I wasn't aware of it (cos I was fast asleep,) but I've been woken by my ex shaking me cos she noticed I'd stopped breathing. I've never woke up choking or in any discomfort tho. But, I believe it can kill you, if you were lying face down or had covers over your face etc... I've had the sleep paralysis thing too, once or twice, that is quite scary. & You can choke on your own tongue, I'z a qualified 1st aider and it's one of the first things you check for if someone ain't conscious / not breathing.