There's confusional arousals, there are states in deeper sleep that can happen where people will go and they'll disappear and they'll take on some other persona. They'll commit some crime, but it's all when they are in a very deep stage of sleep. So you really need to have a very thorough evaluation.

Night terrors are very different from nightmares. A lot of people will think they're the same, but they're really not. Night terrors - you want to look at the time of night when you're having the problem. Night Terrors happen in deep sleep. Nightmares tend to happen in a lighter REM sleep.

Sleep paralysis is something that is actually very common. Many people have it, I've had it myself. And what happens is, when you're in that REM stage of sleep, your brain is very active. You're dreaming your most during that stage, you're mind, your eyes are moving, there's a lot going on. It's like fireworks going on in your brain.

And you cycle throughout so that you do about five to six cycles throughout the night. And we spend more time in REM later on in the night than we do earlier on.

Now narcolepsy is really hard though because they're very tired during the day, they're sleepy during the day and it's managed mostly with medications. So we use medications to help them sleep better at night and to stay away during the day. But there are behavioral things you can do also by changing diet, exercise, having an actual nap schedule.

Nightmares are distinctly different from dreams in the way that people feel them and experience them. So a lot of people think that a nightmare is something where something is chasing them and you have to wake up screaming. Yes, that's one of the more common nightmares that we see is the person chasing someone or they're being chased.

When it comes to the reason why we have nightmares, we're still debating that. It's a new area of research, nightmares. And the way I like to think about it is, our brain - we have stress during the day and our brain needs to learn to process this stress.