You’re in high school again and can’t find your schedule—because there is no schedule.

Your young child falls into a pool, and you have to swim to the bottom to save him. 

Your house is on fire and you can’t find your way out.

In times of intense stress, sleep can be hard to come by. When you finally convince your brain to slow down and you drift off to sleep, suddenly you’re having nightmares and waking up in a cold sweat. What gives?

“Dreams serve a very important purpose,” says M Health Fairview neurologist Michael Howell, M.D., an associate professor in the University of Minnesota Medical School’s Department of Neurology. “They’re your brain’s way of consolidating memories.”

In REM (or rapid eye movement) sleep, the phase in which dreams occur, the brain is busy doing “file compression,” Howell explains. It’s getting rid of information from the day that isn’t important, and it hangs on to the information that is in some way relevant for the long term.

Dreams originate from the brain’s limbic system, which controls both memory and emotion. So perhaps not surprisingly, most dreams are centered on primitive human emotions.

“Joy, laughter, terror, humiliation—all of these are your brain’s way of saying, ‘OK, it’s really important that you remember this for your survival and your coherence with your family and neighbors,’” he says. “Dreams have a nice way of distilling down the essence of what matters.”

Stress, the sleep interrupter

When stress plays a prominent role in a person’s daily life—during a global pandemic or in times of civil unrest, for example—the brain is processing a lot of emotion and new worries.

Couple that with unusual sleep patterns and the dream pump is primed for memorable and often vivid dreaming. If you wake up in the middle of a dream, you’re more likely to recall it in detail, too.

“The brain takes memories that were intensely emotional from the day and replays them,” Howell says. “[A memorable event] doesn’t even need to have actually happened. It could just be something you imagined.”

Howell himself, for instance, has dreamt about his daughter riding her bike into traffic. In his waking life, he merely saw her get close to the edge of the sidewalk as a car passed by. “As far as your brain is concerned, that’s enough,” he says. “Your brain will take that experience, that memory, and replay it while you’re dreaming.”

Almost all parents have dreams about their children in peril, Howell says. Other common—and completely normal, he says— dream themes involve being chased, abandoned, abducted, attacked by an animal, or caught in a fire or riot.

There’s no need to spend time psychoanalyzing the content of your dreams, Howell says. It’s just the brain processing information from the day—and trying to prepare you, should you encounter these scenarios in the future.

Better sleep, better life

Sleep serves many important purposes (see sidebar) besides giving your brain a chance to consolidate memories and process emotions through dreams. And we all could be better at it, Howell says.

Keeping a consistent sleep schedule, even on weekends, sets your body’s internal clock. If the sleep schedule you want isn’t the one that comes naturally to you, Howell says, change it little by little. Avoid digital screens within a couple of hours of your bedtime. Be active during the day, and minimize caffeine and alcohol consumption.

More sleep—most adults need at least seven hours a night, according to the Centers for Disease Control and Prevention— can even help you manage stress more effectively, which may ward off some of those pesky pandemic nightmares.

“Everyone’s brain can function better with better sleep. Making the world a better place,” Howell says with a smile, “that’s what we’re trying to do.”

Make a gift to sleep research at give.umn.edu/giveto/sleep or by contacting Kristen Rasmussen of the University of Minnesota Foundation at 612-625-5192 or kristenr@umn.edu.