What is REM Sleep ?

While the body is sleeping, the brain moves through four different stages of sleep that make up the sleep cycles happening throughout the night. One of these important stages of sleep is Rapid Eye Movement, or REM sleep. If you haven’t guessed by now, this stage of sleep is characterized by the fact that the eyes tend to move in a jerky fashion, back and forth, up and down.

How Is REM Sleep Different from Other Stages?

The other four phases of sleep are often referred to as non-REM or NREM sleep, because they differ significantly from the REM portion of the sleep cycle. REM sleep occurs typically around 90 minutes or so after the person falls asleep, and this stage will last for approximately 10 minutes at the beginning of the night, or up to 30 minutes during the last sleep cycles of the night.

NREM sleep is a time in which the body is repairing itself, growing, gathering energy for the following day, and promoting the immune system. The body is being restored and cared for during NREM sleep, but the brain gets what it needs during the REM portions of the sleep cycle.

During the REM sleep stage, the brain is extremely active, almost as much as when a person is awake. This is the stage in which a person is actively dreaming, and if a person wakes during or just after this phase, they may even remember their dreams. Some scientists refer to this stage as paradoxical sleep because the brain is very active but the body is not.

The body’s activity during REM sleep includes fast irregular breathing, a quicker heart rate, increased blood pressure, and even a difficult regulating body temperature. The brain consumes more oxygen during REM sleep than other sleep stages, and sexual arousal may also occur.

While the brain is very active during this phase of sleep, twitching of the muscles and limbs may be observed. Even so, the body is typically going through a phase of temporary paralysis during REM sleep, which could be a protective measure to prevent the acting out of dreams.

Effects of REM Sleep

Here are some of the things that happen as your brain enters into REM sleep:

Consolidate Memories

It is believed that the brain is more able to consolidate memories when it receives the proper amount of REM sleep. This factor helps with learning, and people can often remember better whatever it is they were taught before falling asleep.

Some scientists indicate that a certain type of plaque, which can be related to Alzheimer’s, is cleared from the brain during REM sleep. This could mean that REM sleep helps prevent and/or minimize the effects of Alzheimer’s and other memory or dementia related diseases.

Better Mood

Dreaming, whether remembered or not, seems to be able to help to take the edges off of our emotional state and strengthen it up. People who experience an adequate amount of REM sleep are typically able to better process their emotions, are less reactive to difficult situations, and may even be less fearful in traumatic events.

Some scientists note that norepinephrine, a stress-associated hormone, is not secreted during REM sleep. This may be a time that the brain is re-setting these hormones to normal levels. The time during REM sleep without the release of norepinephrine could explain why certain people are better equipped to handle the emotions of life when they get enough sleep.

Development of Central Nervous System (CNS)

For infants, time spent in REM sleep may be critical for the development of their brains and nervous systems. During REM sleep, signals are sent to the cerebral cortex of the brain, which takes care of thinking, learning and the organization of information.

Adults also benefit from REM sleep as it allows for the neurotransmitters in the brain to be replenished, and for neural connections to be forms. This impacts memory, learning, and overall brain function.

Why is REM Sleep Important?

Although mysteries still surround the details of sleep, scientist do know that getting REM sleep is vitally important to the functioning of your body and brain. If you don’t get adequate amounts of REM sleep, these could be the effects:

  • Gaining Weight
  • Migraine Headache
  • Compromised Emotional Health
  • Brain Fog
  • Possible Shortened Life Span

According to the National Institute of Neurological Disorders and Stroke, one study in which rats were deprived of REM sleep resulted in significant shortening of their life spans—from 2-3 years to only five weeks! It’s likely that chronic deprivation of REM sleep in humans could have a detrimental effect as well.

How to Improve REM Sleep

  • Avoid alcohol before bed
  • Quit smoking
  • Minimize blue light in the evening
  • Go to bed the same time every night
  • Sleep in a dark room with lower temperatures
  • Avoid prescription sleep medications
  • Try waking up without an alarm clock
  • Check with your doctor if you have chronic insomnia

Drinking alcohol can significantly reduce the amount of REM sleep a person gets during the night, instead keeping them in a lighter, less restorative stage of sleep.

Some people act out their dreams if they have REM sleep behavior disorder, which is not typical. Most people reach a somewhat paralyzed state during REM sleep so that they don’t move around. If you do act out your dreams, talk to your doctor about this to see if there is any help that can be offered.

People spend less time in REM sleep as they age. Babies and young children spend a high percentage of their sleep in REM stages, and this decreases into adolescence and young adulthood. Older adults spend much less time in REM sleep. So if you’re getting on in years and feel like you aren’t getting as much sleep recently, that may be a very normal pattern of life.


In this busy world, it can be very difficult to get enough quality, restorative sleep each and every night. But there are many things you can do to restore your brain and your body to healthy sleep patterns! Getting healthy sleep each night is a choice and can begin with planning for 7-8 hours of sleep, choosing a comfortable mattress, practicing healthy sleep hygiene habits, and talking to a medical professional if you have concerns about your sleep.

Go ahead and get some REM sleep tonight. You’ll feel much better in the morning. Dream on!

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