What is the difference between sleeping and fainting?

What is the difference between sleeping and fainting?

Chris Idzikowski (Director of the Edinburgh Sleep Centre) gives expert video advice on: What is deep sleep?; When are we at our deepest sleep?; If we are unconscious when we sleep, how do we wake up? and more...

The difference between sleeping and fainting is, there can be a variety of things. But let's say for some reason, blood pressure dropped down a little bit. It's a completely disorganized state as far as the brain is concerned. Whereas the state of sleep is one where the brain has made the decision that it's going to move into this different state of being.