AILSA CHANG, HOST:

You don't need me to tell you this - the holidays can be really stressful. You've got the regular stress of your job. You're blowing cash on gifts. Add to that a dash of family dysfunction, and it's truly a special time. And all that anxiety, it needs a place to go.

UNIDENTIFIED WOMAN #1: All right, so do you want me to just tell you my dream?

UNIDENTIFIED WOMAN #2: My anxiety dream - well, one of them anyway...

UNIDENTIFIED WOMAN #3: So you want both my anxiety dreams?

UNIDENTIFIED WOMAN #4: I have three different anxiety dreams to share with you.

UNIDENTIFIED MAN #1: I am amazed that people don't always have anxiety dreams. The only dreams I can remember are anxiety dreams.

CHANG: Why do we have these anxiety dreams? This seemed like a really good excuse to pry into our coworkers' personal lives, so we asked some of them to tell us about their deepest, darkest, most stressful dreams. And maybe we tipped the scales by asking our coworkers because a lot of the anxiety dreams they told us about were about work.

UNIDENTIFIED WOMAN #3: We're in the middle of a show, Morning Edition. It's David Greene and Steve. All of a sudden, all the power goes out.

UNIDENTIFIED WOMAN #5: I am in there directing the live show. Stuff is happening. News is breaking, and suddenly I lose my eyesight.

UNIDENTIFIED WOMAN #6: And someone walks into the studio and hands me this little kitten.

UNIDENTIFIED MAN #2: There's a giant clock on the wall. And it's ticking, ticking, ticking up to 4 o'clock.

UNIDENTIFIED WOMAN #5: And I have to direct the show through feel.

UNIDENTIFIED MAN #2: And I am running, sprinting for the studio.

UNIDENTIFIED WOMAN #7: You get in the studio, the on-air light goes on, and you don't have your script.

UNIDENTIFIED MAN #1: And she can't figure out how to use the mouse. And so I took the mouse from her, but the mouse was suddenly a real-life mouse, like, a little furry mouse, like, a white one.

UNIDENTIFIED MAN #2: At the same time, while I'm trying to run and run and run, I have a vision of Robert Siegel, and he's going...

ROBERT SIEGEL, BYLINE: Where's Stu?

UNIDENTIFIED WOMAN #7: And you have absolute lockjaw. Nothing comes out.

UNIDENTIFIED WOMAN #8: And that's it. And I just have it all the time.

UNIDENTIFIED WOMAN #9: There was a period when I had these every night for a month.

UNIDENTIFIED MAN #1: (Laughter) I died. Like, I didn't die in reality, but I felt horrible, horrible, like, just skin-crawling anxiety. And then I woke up.

UNIDENTIFIED WOMAN #10: So what does it all mean?

ROBERT STICKGOLD: It looks like our dreams serve a function of trying to identify, first of all, information that we have, things that we've learned, stuff that we know that is incomplete in some ways. So we haven't solved some problems.

CHANG: That's Robert Stickgold of Harvard Medical School. He's a cognitive neuroscientist who studies sleep, dreams and memory.

STICKGOLD: And when the brain identifies these areas with lingering questions, it actually spends a lot of time while we're asleep trying to solve those problems. And it tends to be situations where it's imagining how things might turn out. And these are perfect examples. These are things that people worry about might happen. And then it sort of says, OK, let's run with that and see where it goes.

CHANG: I mean, as we heard, work obviously is a pretty good reason for so many anxiety dreams. But here's another common theme courtesy of NPR's Sam Sanders.

SAM SANDERS, BYLINE: I will be in college and there'll be a course - it's usually a mathy (ph) or science kind of class, like calculus or engineering or other things that I don't like. And I'll be going to college the whole semester but not going to that class. And then I'll get a notification that I've missed too many classes and that I have to go to the final or I'll fail everything and I'll flunk out of college and my life will be over and my mother will disown me and I'll have to move out of the house and nothing will ever go my way in life ever again. And then I try to go to the final and I flunk the final, of course.

CHANG: Oh (laughter). Actually, I have a very, very similar recurring anxiety dream. So what's up with that? Are there some themes in anxiety dreams that are just more common than others?

STICKGOLD: There are, absolutely. And I think it's because that there are anxieties that are more common. I've heard a Nobel laureate start a lecture by saying, I had that exam dream again last night. And the whole audience just moaned. I mean, it never stops. And I think what's going on - and that - the exam dream is an excellent example - is that we have, in the course of our lives, taken thousands of exams, each of which is a little bit traumatic. It's sort of like not death by a thousand cuts, but anxiety by a thousand cuts.

So you're - when you're sleeping, your brain's sort of looking through its files, if you will, and it's saying, OK, what's not settled? What's still an issue? And it's all those exams piled on top of each other. It's such a huge pile that it sticks out like a beacon.

CHANG: Do people who identify themselves as anxious people - do those people have more anxiety dreams? Or do anxiety dreams afflict all of us?

STICKGOLD: Well, they certainly afflict all of us. We've done some studies where we looked at emotion in dreams, and I'm very sad to tell you that anxiety is the most common emotion reported during dreams. And in fact, dreams overall tend to be more negative than positive. And in fact, they tend to get more negative as they proceed over the course of a longer dream. It might be that people who are more anxious have more of these dreams, and certainly when you reach the extreme condition of PTSD there's no question. But they have, you know, very high frequencies of these extremely wrought, beyond anxious into terrifying dreams.

CHANG: Yeah. Are there any ways people can limit the amount of anxiety dreams they have? Or are anxiety dreams just part of the human condition and there's nothing any of us can do about it?

STICKGOLD: Well, those are two different questions. I think anxiety dreams are part of the human condition. I think one of the things that the brain does is it asks itself the question, what's bothering me? Because anything that's bothering me is something that I could perhaps spend some time tonight working on and trying to figure out.

CHANG: I wish the brain would ask, what makes me happy tonight?

STICKGOLD: I know. I know. What would I like to dream tonight? What would be fun to dream tonight? But, I mean, what you can do is you can - I mean, and it's not useful to say this - is you can be less anxious. Go on vacation. I know know when I go on vacation, I actually stop worrying. And do my dreams change? I don't think anyone's done this study. One question would be how fast can your dreams change? I don't know if we know the answer to that.

CHANG: Robert Stickgold. Thank you for being with us today.

STICKGOLD: It's been a dream.

(SOUNDBITE OF LONDON FESTIVAL ORCHESTRA PERFORMANCE OF MAX STEINER'S "A SUMMER PLACE THEME") Transcript provided by NPR, Copyright NPR.