What Are Dreams?

This content was created by the National Sleep Foundation


Find out how, when, and what we dream.

Have you ever woken up from a dream that was so vivid and lifelike that it actually seemed real? It's such a surreal experience that it may make you wonder: What exactly is a dream, anyway? Scientists have long tried to figure that out. The basic definition is that dreams are subconscious imaginings that contain sounds, images, and other sensations while you sleep. Below, find out the answers to other frequently asked questions.

When Do You Dream?

Dreams happen most often during REM (rapid eye moment) sleep, which is the deepest stage of sleep. This stage makes up about 20 to 25 percent of adult sleep and occurs in intervals that can last anywhere from a few minutes to 30 minutes. You cycle through REM sleep a number of times during the night, and if you happen to wake up in the morning during that stage of sleep, a dream may seem fresher in your mind.

What Do You Dream?

Dreams can be about, well, anything at all. They can be magical and exhilarating, totally strange, or even horrifying (those could be called bad dreams, nightmares or night terrors). Dreams could include the most obvious individuals in your life—such as family members, friends, and pets—as well as people you've never seen before. They might take place in a familiar setting, like the office where you work. Or the setting might be a faraway location, such as the moon, or a fictional place, such as a main character's home on a television show.

Check out these other informative articles to find out why you dream and how often you do it.