Have you ever been awakened right in the middle of a wonderful dream? Maybe you were floating on the Caribbean in a state of utter bliss, or being chased by outlaws in the Wild West. When you wake up, you probably find yourself a little bummed out that you can’t finish your dream. If this sounds like you, chances are you were woken up during a period of REM sleep. So, what is REM sleep and how is it linked to dreaming? Read on to learn about your REM cycle and how it interacts with your dream world.

What is REM Sleep?

REM sleep, also known as Rapid Eye Movement, is distinct from other sleep stages and is sometimes referred to as paradoxical sleep. During the phases of Non-REM (light and deep) sleep, brain activity slows and changes considerably from its waking state. In REM sleep, your brain remains highly active and functions at levels similar to that of a waking brain. At times, your level of brain activity during REM can actually be higher than when you’re awake. Your heart rate also increases and becomes more variable in REM compared to other stages of sleep. During this phase, your eyes move back and forth constantly underneath closed lids. This rapid eye movement is one of the most marked physical characteristics of this sleep phase.

How Much Time is Spent in REM? Over the course of a night, you spend approximately 25 percent of sleep in the REM phase. REM sleep doesn’t occur all at once. Instead, periods of REM are interspersed among the other stages of sleep as you move through a series of sleep cycles. It typically takes about 90 minutes of sleep to arrive at the first REM period. The first stop of the night in REM sleep is brief, lasting roughly five minutes. Each subsequent return to REM grows longer. REM sleep is predominant in the final third of the night, and the final stage of REM sleep can last 30 minutes. A full night of sleep—typically in the range of seven to nine hours—is necessary to achieve all the restorative benefits of REM sleep.

REM and Your Dreams

Most dreaming occurs during REM sleep. On average, you will spend about two hours per night dreaming. Often those dreams aren’t remembered, but if you wake from REM sleep, you’re more likely to recall what you’ve been dreaming about. Dreaming is one of the great mysteries of the human experience, and of sleep itself. Humans have long wondered about the meaning and purpose of dreams, and cultures have connected dreams to their deepest hopes and fears. Many ancient cultures saw dreams as messages or warnings from the gods. Throughout history, dreams have been regarded as out-of-body explorations for the soul, as a means to communicate with the dead, and as harbingers of “evil” spirits. Sigmund Freud theorized dreams as a landscape in which to explore the repressed emotions and desires of the unconscious mind.

Why Do We Dream?

Dreaming remains a scientific mystery even today. Contemporary investigations of dreaming include exploration of both psychological and neurological functions. Theories of the purpose of dreaming continue to cover wide terrain and often overlap with one another. Some theories posit that dreams are a means to integrate new experiences into your memory and to process emotional and traumatic events as a way to regulate your mood. Other theories suggest dreaming is the brain’s way of de-cluttering itself after a long, active day of acquiring new information. Some scientists think dreams are a response to stimuli gathered throughout the day, while others contend that dreams are a response to the external stimuli that occurs during sleep itself.

It’s clear that the exact purpose of dreaming is still under debate. What we do know is that it’s a unique way to experience memories and thoughts during your REM sleep stage. If you want to get better at remembering your dreams, use a dream journal, or trying some other techniques for dream recall.

Happy dreaming!

“Brain Basics: Understanding Sleep”. National Institute of Neurological Disorders and Stroke.  https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Understanding-Sleep.
“The Characteristics of Sleep”. Healthy Sleep Harvard.  http://healthysleep.med.harvard.edu/healthy/science/what/characteristics.
“The Possible Functions of REM Sleep and Dreaming”. NCBI.  https://www.ncbi.nlm.nih.gov/books/NBK11121/.
“Techniques for Dreaming”. SleepScore Labs.  https://sleepscoredev2.wpengine.com/articles/techniques-for-dreaming.