Dr. Matthew Walker

But I think this is a very good, important point where you could almost say the very best person to interpret your dreams is probably you.

so nightmares how do we define a nightmare in sort of science clinically it's a little bit tricky but usually the way we define it is it's a strongly unpleasant dream that causes some time of daytime displeasure so in other words some type of daytime dysfunction or distress

So everyone can have a bad dream, but when you go up into your waking life and about your waking day, it doesn't seem to bother you too much.

And maybe we'll just say, that's a bad dream.

When it really becomes a nightmare is when I almost think of it as though you wake up

And that blanket of strong nightmare emotion is still wrapped around you.

And you can feel it.

You can just know there's my emotional state is still heavy.

And I know exactly where it came from.

And it was from that nightmare.

And throughout the day, you don't seem to be able to de-robe yourself from that cloaked affect of the nightmare.

It drenches you almost.

That's where it really starts to become unpleasant.

And we actually do have a clinical category.

It's called nightmare disorder.

And the way we typically define that is the same thing, as I said, a very unpleasant dream that causes some type of daytime distress.

And it's happening at least once a week.

At that point, we start to move it into this category of nightmare disorder.

What are nightmares doing, if anything at all?

There are at least two theories.