Table of ContentsView AllTable of ContentsSignsWhen It HappensImpactChallengesREM Sleep DisordersHow to Improve It

Table of ContentsView All

View All

Table of Contents

Signs

When It Happens

Impact

Challenges

REM Sleep Disorders

How to Improve It

Close

This period of the sleep cycle usually takes place about 90 minutes after a person first falls asleep.Each REM sleep cycle typically occurs every 90 to 120 minutes. People spend approximately 25% of their total time asleep in REM sleep.

This article discusses the signs and effects of REM sleep. It also explores some steps you can take to improve your REM sleep.

Signs of REM Sleep

The brain and body go through a number of changes that are characteristic of this stage of sleep. Some key signs of REM sleep include:

Most people also experience a state of temporary paralysis known as atonia. During REM sleep, the muscles that prevent body movements become active, leading to temporary paralysis. This is a normal function of REM sleep and prevents you from physically acting out dreams.

REM Sleep vs. NREM Sleep

REM SleepLoss of muscle toneFaster brain wavesIncreased dreamingNREM SleepDecreased energy useSlow brain wave activityProduction of growth hormone and adenosine triphosphate

REM SleepLoss of muscle toneFaster brain wavesIncreased dreaming

Loss of muscle tone

Faster brain waves

Increased dreaming

NREM SleepDecreased energy useSlow brain wave activityProduction of growth hormone and adenosine triphosphate

Decreased energy use

Slow brain wave activity

Production of growth hormone and adenosine triphosphate

When Does REM Sleep Happen?

There are four different stages of sleep. NREM sleep accounts for the first three stages, and REM sleep is considered the fourth stage.

It is important to note that these stages do not follow a perfectly sequential pattern as you sleep. During the first sequence, stages 1, 2, and 3 occur, and then stage 2 begins again. It is after this second occurrence of stage 2 sleep that REM sleep first appears.

A complete sleep cycle takes roughly 100 minutes to complete. Four to five cycles may occur each night, depending on how long a person sleeps.

Sleep is essential for health and well-being. While all stages are important, deep sleep (or stage 3 sleep) tends to have the greatest impact on how rested people feel the next day.

Impact of REM Sleep

REM sleep plays an important role in brain development as well as other functions including mood, dreaming, and memory.

Dreams

Researchers do not fully understand the exact reasonswhy we sleep. They do know that newborns dream and that depriving rats of REM sleep greatly shortens their lives. Other mammals and birds also have REM sleep stages, but cold-blooded animals such as turtles, lizards, and fish do not.

Dreams can take place during any of the stages of sleep, but those that occur during REM sleep tend to be the most frequent and vivid.

1:409 Common Dreams and Their Interpretations

1:40

9 Common Dreams and Their Interpretations

Brain Development

Research suggests that REM sleep serves an important role in the development of the central nervous system (CNS) during infancy. The high activity levels in the brain during this stage of sleep may play a role in developing and strengthening neural connections.

Memory

Dreams may be one way that the brain consolidates memories. Thedream timecould be a period when the brain can reorganize and review the day’s events and connect new experiences to older ones. Because the body is shut down, the brain can do this without additional input coming in or risking the body “acting out” the day’s memories.

Some researchers believe that dreams are more like a background “noise” that is interpreted and organized. Thisactivation-synthesis theorysuggests that dreams are merely the brain’s attempt to make sense of random signals occurring during sleep.

Some people have more control over their dreams than others. For these people, the last thoughts before going to bed may influence the content of a dream.

Emotional Processing

REM sleep is also believed to play an important part in emotional processing. Dreaming may be a part of this process. Research suggests that lack of sleep contributes to decreased emotional memory consolidation and poor encoding of emotional memory.

Effects of a Lack of REM Sleep

REM sleep plays an important role in a number of functions, including learning and memory. Interruptions to REM sleep can sometimes result in problems. As a result, the lack of REM sleep is linked to several health concerns, including the following.

Increased Weight

Reduced REM sleep is associated with changes in leptin levels and may be associated with increased appetite and weight.

Memory Consolidation

If people are taught various skills and then deprived of REM sleep, they often cannot remember what they were taught.

REM sleep usually begins after a period ofdeep sleepknown as stage 3 sleep. An area of the brain called the pons—where REM sleep signals originate—shuts off signals to the spinal cord. That causes the body to be immobile during REM sleep.

When the pons doesn’t shut down the spinal cord’s signals, people will act out their dreams. This can be dangerous because acting out dreams without input from the senses can lead to accidents and physical harm such as running into walls and falling down stairs. This condition is rare and different from more common sleepwalking and known as REM sleep behavior disorder.

Sleep Disorders That Affect REM Sleep

There are a number of different sleep disorders that can cause problems with REM sleep. These include:

How to Improve REM Sleep

There are things that you can do to make the most of your REM sleep each night.

Watch Your Alcohol Intake

Keep your alcohol intake light before going to bed. Research has found that even moderate alcohol intake in the evening can interfere with REM sleep. Light alcohol intake doesn’t seem to have the same impact, but moderate to heavy consumption delayed the onset of REM sleep and led to fewer REM sleep phases during the night.

Remember Your Dreams

Some people claim that they have lucid dreams, which are dreams in which they can participate and change the dream as it develops.Lucid dreamingcan be triggered through a number of techniques, though little research has been done on it.

If you or a loved one are struggling with a sleep disorder, contact theSubstance Abuse and Mental Health Services Administration (SAMHSA) National Helplineat1-800-662-4357for information on support and treatment facilities in your area.For more mental health resources, see ourNational Helpline Database.

If you or a loved one are struggling with a sleep disorder, contact theSubstance Abuse and Mental Health Services Administration (SAMHSA) National Helplineat1-800-662-4357for information on support and treatment facilities in your area.

For more mental health resources, see ourNational Helpline Database.

17 Sources

Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Cleveland Clinic.Sleep basics.

Peever J, Fuller PM.Neuroscience: A distributed neural network controls REM sleep.Curr Biol. 2016;26(1):R34-R35. doi:10.1016/j.cub.2015.11.011

Shrivastava D, Jung S, Saadat M, Sirohi R, Crewson K.How to interpret the results of a sleep study.J Community Hosp Intern Med Perspect. 2014;4(5):24983. doi:10.3402/jchimp.v4.24983

Centers for Disease Control and Prevention.How much sleep do I need?

AAST.Sleep stages: The evolution of sleep medicine in neurology (part one).

Sleep Foundation.Stages of sleep.

Johns Hopkins Medicine.The science of sleep: Understanding what happens when you sleep.

The National Sleep Foundation.How often do you dream?

National Institute of Neurological Disorders and Stroke.Brain Basics: Understanding Sleep.

Dumoulin bridi MC, Aton SJ, Seibt J, Renouard L, Coleman T, Frank MG.Rapid eye movement sleep promotes cortical plasticity in the developing brain.Sci Adv. 2015;1(6):e1500105. doi:10.1126/sciadv.1500105

Mutz J, Javadi AH.Exploring the neural correlates of dream phenomenology and altered states of consciousness during sleep.Neurosci Conscious. 2017;2017(1):nix009. doi:10.1093/nc/nix009

Tempesta D, Socci V, De Gennaro L, Ferrara M.Sleep and emotional processing.Sleep Med Rev. 2018;40:183-195. doi:10.1016/j.smrv.2017.12.005

Olson CA, Hamilton NA, Somers VK.Percentage of REM sleep is associated with overnight change in leptin.J Sleep Res. 2016;25(4):419-425. doi:10.1111/jsr.12394

Boeve BF.REM sleep behavior disorder: Updated review of the core features, the REM sleep behavior disorder-neurodegenerative disease association, evolving concepts, controversies, and future directions.Ann N Y Acad Sci. 2010;1184:15–54. doi:10.1111/j.1749-6632.2009.05115.x

Ebrahim IO, Shapiro CM, Williams AJ, Fenwick PB.Alcohol and sleep I: Effects on normal sleep.Alcohol Clin Exp Res. 2013;37(4):539-49. doi:10.1111/acer.12006

Voss U, Holzmann R, Tuin I, Hobson JA.Lucid dreaming: a state of consciousness with features of both waking and non-lucid dreaming.Sleep. 2009;32(9):1191–1200. doi:10.1093/sleep/32.9.1191

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