What is the rem phase of sleep

REM & NREM, Sleep Stages, Good Sleep Habits & More

What is sleep?

You may think nothing is happening when you sleep. But parts of your brain are quite active during sleep. And enough sleep (or lack of it) affects your physical and mental health. When you sleep, your body has a chance to rest and restore energy. A good night’s sleep can help you cope with stress, solve problems or recover from illness. Not getting enough sleep can lead to many health concerns, affecting how you think and feel.

During the night, you cycle through two types of sleep: non-rapid eye movement (non-REM) sleep and rapid eye movement (REM) sleep. Your brain and body act differently during these different phases.

What happens in the brain during sleep?

Researchers continue to study sleep and its effect on us. While we’ve learned a lot about sleep, there’s still much that’s unknown.

We know that brain chemicals are very involved in our sleep cycle. Neurotransmitters are chemicals that help the nerves communicate. They control whether we’re awake or asleep, depending on which neurons (nerve cells) they’re acting on:

  • Neurons in the brainstem (where the brain and spinal cord meet) produce neurotransmitters called serotonin and norepinephrine. These chemicals keep our brain active when we’re awake.
  • Neurons located at the base of the brain are responsible for us falling asleep. It seems these neurons turn off the signals that keep us awake.

Why do we need sleep?

Sleep helps us in many ways. We need it for:

  • Growth: In children and young adults, deep sleep (sleep that’s harder to wake from) supports growth. The body releases growth hormone during this type of sleep. The body also increases production of proteins, which we need for cell growth and to repair damage.
  • Nervous system function: A lack of sleep affects our memory, performance and ability to think clearly. If a person is severely sleep deprived, they may even experience neurological problems such as mood swings and hallucinations. Sleep also helps our nerve cells. They can repair themselves, so they function at their best. And certain nerve connections get a chance to turn on, strengthening our brain and thinking ability.
  • Survival: Researchers don’t fully understand why sleep is so essential. But studies in animals have shown that getting deprived of REM sleep can shorten lifespans. Lack of sleep may harm the immune system, which protects us from infections.
  • Well-being: People who don’t get enough sleep are at higher risk for developing various health conditions including obesity, diabetes and heart problems.

What are the stages of sleep?

When you sleep, your brain goes through natural cycles of activity. There are four total stages of sleep, divided into two phases:

  • Non-REM sleep happens first and includes three stages. The last two stage of non-REM sleep is when you sleep deeply. It’s hard to wake up from this stage of sleep.
  • REM sleep happens about an hour to an hour and a half after falling asleep. REM sleep is when you tend to have vivid dreams.

As you sleep, your body cycles through non-REM and REM sleep. You usually start the sleep cycle with stage 1 of non-REM sleep. You pass through the other stages of non-REM sleep, followed by a short period of REM sleep. Then the cycle begins again at stage 1.

A full sleep cycle takes about 90 to 110 minutes. Your first REM period is short. As the night goes on, you’ll have longer REM sleep and less deep sleep.

What is non-REM sleep?

Three stages make up non-REM sleep.

Stage 1:

This stage of light sleeping lasts for five to 10 minutes.

  • Everything starts to slow down, including your eye movement and muscle activity.
  • Your eyes stay closed. If you get woken from stage 1 sleep, you may feel as if you haven’t slept at all. You may remember pieces of images.
  • Sometimes, you may feel like you’re starting to fall and then experience a sudden muscle contraction. Healthcare providers call this motion hypnic myoclonic or hypnic jerk. Hypnic jerks are common and not anything to be concerned about as this occurrence is unlikely to cause any complications or side effects.

Stage 2:

  • This period of light sleep features periods of muscle tone (muscles partially contracting) mixed with periods of muscle relaxation.
  • Your eye movement stops, heart rate slows and body temperature decreases.
  • Brain waves become slower. Occasionally, you’ll have a burst of rapid waves called sleep spindles.
  • Your body prepares to enter deep sleep.

Stages 3

  • This stage is deep sleep.
  • During this stage, your brain produces delta waves, very slow brain waves.
  • It’s hard for someone to wake you up during this stage.
  • You have no eye movement or muscle activity.
  • If you’re woken up, you may feel groggy and disoriented for a few minutes.

What happens during non-REM sleep?

During non-REM stages, your body:

  • Builds bone and muscle.
  • Repairs and regenerates tissues.
  • Strengthens the immune system.

As you age, you get less non-REM sleep. Older adults get less deep sleep than younger people.

What is REM sleep?

When you enter REM sleep, brain activity increases again, meaning sleep is not as deep. The activity levels are like when you’re awake. That’s why REM sleep is the stage where you’ll have intense dreams.

At the same time, major muscles that you normally control (such as arms and legs) can’t move. In effect, they become temporarily paralyzed.

Usually, REM sleep arrives about an hour and a half after you go to sleep. The first REM period lasts about 10 minutes. Each REM stage that follows gets longer and longer.

The amount of REM sleep you experience changes as you age. The percentage of REM sleep:

  • Is highest during infancy and early childhood.
  • Declines during adolescence and young adulthood.
  • Declines even more as you get older.

What else happens to the body in REM sleep?

Besides increased brain activity and muscle relaxation, your body goes through a series of changes during REM sleep. These changes include:

  • Faster breathing.
  • Increased heart rate and blood pressure.
  • Penile erections.
  • Rapid eye movement.

What affects sleep quality?

Chemical signals in the brain influence our sleep and wake cycles. Anything that shifts the balance of these neurotransmitters can make us feel drowsier or more awake. For example:

  • Alcohol may help people fall into a light sleep. But it reduces the deeper stages of sleep and REM sleep and leads to more disrupted sleep.
  • Caffeine and pseudoephedrine (drug ingredient) can stimulate the brain. They may cause insomnia, an inability to sleep. Watch out for caffeinated drinks such as coffee and drugs such as diet pills and decongestants.
  • Medications such as antidepressants can cause less REM sleep.
  • People who smoke heavily often sleep lightly and have less REM sleep. They may wake up after a few hours because they experience nicotine withdrawal.
  • Very hot or cold temperatures can disrupt REM sleep. We’re less able to regulate body temperature during REM sleep.

How much sleep do I need?

Many factors affect how much sleep you need. Age is a big factor:

  • Infants need about 16 hours a day.
  • Toddlers and preschoolers need about 12 hours.
  • Teenagers need about nine hours.
  • Adults need seven to eight (though some are fine with five and others need closer to 10).
  • Pregnant people often need more sleep during the first trimester.

What is a sleep debt?

If you haven’t slept well or long enough for a few days, you might create a sleep debt. Once your debt builds up, you may feel physically and mentally exhausted. Try to make sure you get enough sleep every night to avoid creating this debt. You can’t necessarily make up your debt by sleeping a lot on the weekends. It’s best to get enough sleep all week long.

Can we adapt to needing less sleep?

Generally, people don’t adapt to getting less sleep than they need. You may feel like you’re used to reduced sleep, but it still affects your function. For example, it can harm your judgment and reaction time.

What is sleep deprivation?

When you’re sleep deprived, you’re not getting the total amount of sleep you need. Signs of sleep deprivation include:

  • Falling asleep within a few minutes of lying down.
  • Feeling drowsy during the day.
  • Nodding off for microsleeps — short periods of sleep during the day when you’re otherwise awake.
  • Sleep deprivation can be dangerous. Driving while tired causes about 100,000 car accidents each year, according to the National Highway Traffic Safety Administration. It also causes 1,500 deaths. If you feel tired on the road, pull over. It’s not safe to drive if you’re drowsy.

What are sleep disorders?

According to the American Sleep Association, at least 40 million Americans experience sleep disorders each year. Another 20 million have occasional sleep issues. These disorders cause sleep deprivation, leading to problems with work, school, driving and social activities.

There are more than 70 sleep disorders. A few, known as disruptive sleep disorders, lead to moving around or making sounds. Other sleep disorders involve food. And some sleep disorders overlap with psychiatric conditions. If you have problems with sleep or feel very tired, talk to your healthcare provider about a possible sleep disorder.

Some of the most common sleep disorders include:

  • Insomnia disorder: Many people experience insomnia at some point in their lives, with trouble falling or staying asleep. Sleeping pills can help in the short-term but behavioral strategies to improve sleep including cognitive behavioral therapy for Insomnia (CBT-i) is a much better long term solution.
  • Narcolepsy: You may suddenly fall asleep during the day, even if you had a good sleep the night before. These “sleep attacks” can last a few seconds or up to 30 minutes. Talk to your provider about your symptoms and additional testing will need to be completed to diagnosis this sleep disorder.
  • Restless legs syndrome (RLS): You may feel unpleasant sensations in your legs (such as prickling or tingling). You may also have an urge to move your legs to get relief. If you have RLS, talk to your healthcare provider about medication to help improve symptoms.
  • Sleep apnea: You may experience periods of interrupted breathing while you sleep, a condition called sleep apnea. Often, getting polysomnography (sleep study) in a sleep center is the best way to get properly diagnosed and treated. Sometimes, weight loss or not sleeping on your back can help. But you may need a special device to help you breathe while you sleep.
  • Snoring: People who regularly snore can have disturbed sleep. They can also disturb the sleep of their bed partner. Snoring often leads to feeling tired during the day. Several treatment options are available for snoring.

What are good sleep habits?

Good sleep habits, also called good sleep hygiene, are practices to help you get enough quality sleep.


  • Have a sleep schedule: Go to sleep and wake up around the same time every day, even on weekends and vacations.
  • Clear your mind before bed: Make a to-do list early in the evening, so you won’t stay awake in bed and worry about the next day.
  • Create a good sleep environment: Make sure your bed and pillows are comfortable. Turn down the lights and avoid loud sounds. Keep the room at a comfortable temperature.
  • Exercise every day: Stay active but try to avoid exercising during the few hours right before bed.
  • Relax: Before bed, take a warm bath, read or do another relaxing activity.
  • See your healthcare provider: If you’ve been having trouble sleeping or feel extra drowsy during the day, talk to your provider. There are many treatments available for sleep disorders.


  • Consume caffeine, nicotine and alcohol late in the day: These substances can interfere with your ability to fall and stay asleep.
  • Lie in bed awake: It’s better to do a soothing activity, like reading, until you feel tired.
  • Nap during the day: A short nap (less than 30 minutes) is OK if you’re very sleepy. But try to avoid naps after 3 p.m.
  • Think negative thoughts: Try to avoid a negative mindset when going to bed, such as, “If I don’t get enough sleep now, I won’t get through my day tomorrow!”
  • Use electronics right before bed: Electronics, such as your phone or tablet, can interfere with your body’s production of melatonin. This hormone gets released before bed to help you feel tired.

A note from Cleveland Clinic

Far from being a state of doing nothing, sleep is an essential part of our lives. It helps our body rest, recharge and repair. There are four sleep stages — three in the non-REM phase plus REM sleep. Many factors can affect sleep quality, including the food and drink you consume before bed and room temperature. Many people experience trouble sleeping now and then. But if you think you may have a sleep disorder, talk to your healthcare provider. Common sleep disorders include insomnia (trouble falling asleep) and sleep apnea (breathing trouble during sleep). Your provider can help you get the diagnosis and treatment you need.

REM Sleep: What It Is and Why It Matters

Rapid eye movement (REM) sleep goes by many names, including active sleep, desynchronized sleep, paradoxical sleep, rhombencephalic sleep, and dream sleep. Many people have been told REM sleep is the stage of sleep in which you dream, but REM is involved in a host of important functions, from brain development to emotional processing.

We explore the mysteries of REM sleep, why we need REM sleep, what happens when we don’t get enough REM sleep, and the sleep disorders associated with this stage of sleep.

What Is REM Sleep?

Rapid eye movement (REM) sleep is a stage of sleep associated with dreaming and memory consolidation. REM sleep was first discovered in the 1950s, when scientists studying sleeping infants noticed that there were distinct periods when their eyes moved rapidly from side to side. These rapid eye movements, or REMs, earned REM sleep its name.

What Happens During REM Sleep?

During REM sleep, your eyes move rapidly behind your closed eyes, your heart rate speeds up, and your breathing becomes irregular. In contrast to other stages of sleep, in which your brain waves slow down, your brain is highly active during REM sleep, and your brain waves become more variable.

During REM sleep, much of your body operates similarly to how it does when you’re awake, except your eyes are closed and you experience a temporary loss of muscle tone. Researchers have hypothesized that this is a protective measure, meant to stop you from acting out your dreams and injuring yourself. However, now that scientists know we can experience dreams during non-REM sleep stages when our bodies are not paralyzed, this hypothesis is losing steam.

Various land-based species experience REM sleep, including humans and other mammals, reptiles like the Australian bearded dragon, and most birds. Although, REM sleep can look different depending on the species. For example, owls don’t experience actual rapid eye movements during REM sleep since they can’t move their eyes in their skulls. And, some birds only lose muscle tone in certain areas, like the neck, during REM sleep, so their head can rest while they keep standing on one foot.

REM Vs. Non-REM Sleep

REM sleep is one of the most fascinating stages of sleep, in part because it’s so different from other stages of sleep. In non-REM sleep, your eyes don’t move, your brain waves are much slower, and you maintain some muscle tone. Traits unique to REM sleep that differentiate it from non-REM sleep include:

  • Brain wave activity that’s more similar to wakefulness than any other stage of sleep
  • Complete loss of muscle tone vs. the partial muscle tone of non-REM sleep
  • Irregular breathing vs. the steady, slower breathing of non-REM sleep
  • A rise in heart rate vs. the slowdown experienced in non-REM sleep
  • The ability to be awoken more easily than during non-REM sleep

When Does REM Sleep Occur?

You experience your first cycle of REM sleep about 60 to 90 minutes after falling asleep. As part of a full night’s sleep, you cycle through four stages of sleep multiple times: three stages of non-REM sleep, followed by one stage of REM sleep. Each cycle through all the sleep stages takes 90 to 120 minutes to complete. With each new cycle, you spend increasing amounts of time in REM sleep, with most of your REM sleep taking place in the second half of the night.

Each stage of sleep is distinct:

  • Stage 1 (Light Sleep): As your brain slows down, low-amplitude mixed-frequency (LAMF) activity replaces the alpha brain waves that took over as you became drowsy. Your body has some muscle tone, and your breathing is regular.
  • Stage 2 (Light Sleep): Your heart rate and body temperature both decrease. Sleep spindles and K-complexes, specific brain wave patterns, begin occurring as you continue transitioning toward deep sleep.
  • Stage 3 (Deep Sleep): Your brain waves at this stage, called delta waves, are at their slowest of the night. Waking you is difficult, and those who are roused from this stage experience sleep inertia, a short period of fogginess and impaired cognitive performance. In deep sleep, your body physically repairs itself, boosting your immune system and restoring your bones, muscles, and tissue.
  • Stage 4 (REM sleep): Your brain activity in this stage looks similar to how it looks when you are awake. You experience a loss of muscle tone, except for your eyes, which move rapidly. Your breathing becomes irregular and your heart rate rises.



Why Is REM Sleep Important?

All sleep is important, but REM sleep in particular plays an important role in dreaming, memory, emotional processing, and healthy brain development.


A majority of your dreams take place during REM sleep. However, REM is not the only stage in which dreams occur — that’s actually a common myth about sleep. That said, the dreams you experience in REM sleep are usually more vivid than non-REM sleep dreams.

Emotional Processing

Your brain processes emotions during REM sleep. Dreams, which are more vivid in REM sleep, may be involved in emotional processing. Also, your amygdala, the part of your brain that processes emotions, activates during REM sleep.

Memory Consolidation

During REM sleep, your brain processes new learnings and motor skills from the day, committing some to memory, maintaining others, and deciding which ones to delete. Some memory consolidation also takes place in deep sleep, a non-REM stage.

Brain Development

Researchers hypothesize REM sleep promotes brain development, since newborns spend most of their sleep time in REM. Adding to the evidence is that animals born with less developed brains, such as humans and puppies, spend even more time in REM sleep during infancy than those that are born with more developed brains, like horses and birds.

Wakefulness Preparation

REM sleep, through its activation of our central nervous system, might help us get ready to wake back up. This may explain why we spend increasing amounts of time in REM sleep as the night progresses and why we are easier to wake up during this stage.

How Much REM Sleep Do You Need?

We need the most REM sleep as infants and children, when our brains are still developing. Newborn babies spend eight hours in REM sleep each day. By adulthood, we only need an average of two hours of REM sleep each night.

Different species require different amounts of REM sleep. Some mammals, like horses and elephants, can get by with little to no REM sleep, while cats, platypuses, and ferrets may spend up to eight hours each day in REM sleep. Like humans, most mammals also spend a greater proportion of their sleep time in REM sleep when they are infants than they do as adults.

Your body alters your sleep duration both over the course of your life and from day-to-day according to your biological and energetic needs. Similarly, how much time you spend in the specific stages of sleep, including REM, can vary from night to night based on what your body needs.

For example, both animal and human studies have documented increased REM sleep after learning. In a study of rats, those who learned a new maze spent more time in REM sleep for nearly a week afterward. Another study monitored the impacts of sleep on the working memory of healthy college students. Each day, the students were given two tests, with one group taking a nap between the tests and the other group staying awake. The group that napped had higher accuracy, and, the more time they spent in REM sleep during their nap, the higher their accuracy.

What Happens if You Don’t Get Enough REM Sleep?

Multiple studies of both humans and animals suggest that being deprived of REM sleep interferes with memory formation. However, memory problems associated with a loss of REM sleep could be due to overall sleep disruption, since those often occur together. Also, studies of the few rare individuals who do not experience REM sleep show that they do not experience problems with memory or learning. That said, REM sleep deprivation disrupts the brain’s ability to generate new cells. More research is needed to better understand the effects of REM sleep deprivation.

In general, missing out on sleep isn’t recommended. Sleep affects various aspects of your overall health, from your mood to your immune system. When you don’t get enough sleep, you experience sleep deprivation. Signs of sleep deprivation can include:

  • Difficulty concentrating during the day
  • Excessive daytime sleepiness
  • Forgetfulness or poor memory

Over time, chronic sleep deprivation is linked to health conditions like diabetes, depression, obesity, and cardiovascular disease.

Without adequate sleep, your cognitive performance will decline. You may find yourself forgetting things more often, as working memory is highly affected by sleep deprivation. In fact, short sleepers, who regularly sleep fewer than six hours per night, can experience the same impairments to their working memory as people who haven’t slept for two nights in a row. Since you get most of your REM sleep in the second half of the night, short sleepers spend less time in REM. Certain medications, such as those commonly used to treat anxiety and depression, may also suppress REM sleep.

Sleep Disorders Associated With REM Sleep

Certain sleep disorders are associated with abnormal REM sleep. These include REM sleep behavior disorder (RBD), narcolepsy, and nightmare disorder:

  • REM Sleep Behavior Disorder (RBD): People with RBD don’t always experience muscle paralysis during REM sleep, so sometimes they act out their dreams. They may shout, punch, kick, or jerk in their sleep, which can lead to them injuring themselves or their sleep partner. RBD may be caused by a breakdown in the area of the brainstem responsible for regulating REM sleep. RBD often precedes the development of a neurodegenerative disease.
  • Narcolepsy: When they’re awake, people with narcolepsy can experience episodes of cataplexy. Cataplexy involves a sudden loss of muscle tone and is thought to occur because a person falls into REM sleep instantly, from wakefulness. Other symptoms of narcolepsy include excessive daytime sleepiness, disrupted REM sleep, and hypnagogia, or dream-like hallucinations that occur right before falling asleep. Narcolepsy appears to be caused by a loss of orexin neurons in the hypothalamus.
  • Nightmare Disorder: Nightmares usually occur during REM sleep. A person with nightmare disorder regularly experiences intense and distressing nightmares. Nightmare disorder can be brought on by stress, childhood trauma, and other frightening experiences.
  • Obstructive Sleep Apnea (OSA) and Central Sleep Apnea (CSA): Although sleep apnea disorders do not only occur during the REM sleep stages, they do affect the amount of REM sleep a person obtains. In sleep apnea, a person experiences lapses in breathing as they sleep. When these lapses occur during REM, they often move to a lighter sleep cycle in order to continue breathing. As a result, people with sleep apnea tend to spend less time in REM sleep than others and experience excessive daytime sleepiness.

When to Talk to Your Doctor

If you notice symptoms of sleep deprivation, or believe you might have a sleep disorder like REM sleep behavior disorder or nightmare disorder, talk to your doctor. They can help you determine the cause of your sleep issues and develop a treatment strategy to improve your sleep.

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See More

REM sleep was longer in married people

REM sleep was longer in married people than in single and unmarried people (76.5 minutes versus 62.8 minutes). This result was obtained by scientists from Norway when they analyzed the phases of sleep in married (married) people and those who have never been married. Perhaps it's all about the sense of security and low levels of stress in people who are married. Study published in Frontires in Psychiatry .

Human sleep is divided into phases of REM and non-REM sleep, which are repeated during the night. Non-REM sleep usually occurs immediately after falling asleep. Scientists believe that it is important for the processes of remembering and structuring memory after waking time. REM sleep is much shorter (10-15 minutes) and follows non-REM sleep to complete the cycle. In total, there can be about five such cycles per night, while the proportion of REM sleep is gradually increasing.

In English, REM sleep is called REM - rapid eye movement. It got its name because of the movement of the eyeballs under the closed eyelids, which is characteristic of it. In general, during this phase, increased brain activity is observed, breathing and heart rate increase. The REM sleep phase plays an important role in maintaining the normal functioning of the body, but at the same time it itself is vulnerable to the influence of external factors. Its disorders are associated with insomnia, depression, and stress. It even affects life expectancy: a decrease in REM sleep has been associated with an increase in all-cause mortality.

Henning Johannes Drews and Annika Drews from the Norwegian University of Science and Technology studied the effect of marriage on the duration of REM sleep. They used participant data from the Sleep Heart Health Study. Its participants underwent polysomnography (sleep study) at home: the duration of sleep phases was measured on the resulting diagrams (hypnograms). The study participants also collected socio-demographic data, and then divided them into two groups of 69a person in each: those who are married and those who have never been in it. Groups were compared using Student's t-test or Wilcoxon's t-test.

Married people had longer REM sleep than never married people: on average 76.5 minutes versus 62.8 minutes ( p = 0.003). They also had more REM sleep per night (20.5 percent versus 17.1 percent, p = 0.001). NREM sleep did not differ between groups (p ≥ 0.29).

Research shows that close relationships in marriage (and sleeping together) are associated with increased REM sleep. Drews explains the results by saying that REM sleep acts as a link between marital relationships and mental health. REM sleep is also involved in the formation of episodic (about autobiographical events) and emotional memory, which are associated with socialization. Sleeping with a partner creates a feeling of security, reduces stress levels, and also maintains body temperature (during REM sleep, the ability to maintain temperature decreases). Among the limitations in the study, the scientists cite the inability to obtain data that unmarried people actually slept alone. In the future, they are going to conduct research with a more careful separation of people who sleep together and people who sleep alone.

REM sleep is still a mystery and is still widely researched. Japanese neuroscientists a few years ago identified a set of neurons that control REM sleep. It turned out that these neurons are located in the pons Varolii

Anastasia Kuznetsova

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how they differ and how to sleep better

Many have heard that sleep is divided into slow and fast phases, but not everyone knows what they are. Today we will talk about what fast and slow sleep means, what features each phase has and what significance they have for a person.

VOICE edition

The branch of medicine called somnology deals with the study of sleep. Somnologists analyze brain activity and physiological reactions during sleep using special devices. One of the leading methods is polysomnography - a comprehensive study of a patient's sleep, in which the equipment records the frequency and depth of breathing, muscle contractions, body position, transmission of nerve impulses, heart function and many other parameters. As a result, a hypnogram is obtained - a graph that reflects information about the structure of sleep, including its quality during the phases of REM and non-REM sleep.

Specialists have an effective tool with which it is easy to distinguish between REM and non-REM sleep - this is an electroencephalogram. Without special devices, it is quite difficult to understand whether slow sleep or fast sleep. Most likely, if a person moves his arms or legs, he is in REM sleep. During non-REM sleep, body temperature drops, breathing slows down, and muscles relax.

REM sleep

REM sleep is the phase during which the information received during the day is processed. Studies have found that during REM sleep, brain activity is practically the same as during wakefulness. REM sleep is important for the formation of memories and the consolidation of skills.

REM sleep can be determined by eye movements and irregular breathing. A person in REM sleep can move his hands. Body temperature and heart rate during this period are unstable and can fluctuate from low to high values.

REM sleep normally takes 20-25% of the total sleep time. It comes about an hour and a half after falling asleep and then repeats every hour and a half, each time becoming longer. Especially long REM sleep is observed in the morning hours.

Non-REM sleep

Non-REM sleep is the phase during which physiological rest and tissue regeneration occurs. It is at this time that the “recharging” of the brain, the structuring of memory takes place. A person in the non-REM sleep phase has a decrease in blood pressure and body temperature. Muscles are relaxed, breathing becomes rarer.

Normally, non-REM sleep takes up 75% of the total sleep time. It is divided into three stages, which scientists designate as N1, N2, N3.

N1 (light sleep) is the transitional stage between falling asleep and waking. During this phase of non-REM sleep, phenomena such as hypnagogic jerk (feeling of falling and startling when falling asleep), visual, auditory and tactile hallucinations, sleep paralysis, sleepwalking, sleep-talking can occur.

N2 - body temperature drops, muscles relax, a person completely disconnects from reality. Normally, N2 slow-wave sleep takes up half the time of all sleep and occurs in segments of about 20 minutes.

N3 is a deep sleep during which blood pressure decreases and breathing becomes rare. At this stage, body tissues are restored, hormones are produced and metabolites are excreted. The brain, meanwhile, is engaged in "archiving" memories of events, moving them from short-term memory to long-term memory.

How to increase non-REM sleep

With a lack of non-REM sleep, the body's resistance decreases, immunity decreases and brain activity slows down. It is more difficult for you to concentrate even on familiar tasks, lethargy and anxiety appear. There may be malfunctions in the endocrine system and hormone production. A reduced phase of non-REM sleep also increases the risk of Alzheimer's disease, heart and vascular diseases. Obviously, in order to maintain health, it is necessary to maintain the normal duration of this sleep phase. To increase the duration of non-REM sleep, it is important to follow a few rules.

  1. Scheduled sleep. Take care of your routine. Getting up and going to bed at the same time is definitely a healthy habit.
  2. Movement is life. During the day (just not before bedtime!) Move more. So the brain cells will receive more oxygen, and this will help to establish biological rhythms.
  3. Neither cold nor hot. Ensure that the temperature in the room is comfortable for sleeping. Ventilate the room regularly.
  4. Put your phone down. Gadgets have a bad effect on the quality of sleep. An hour and a half before leaving for Morpheus, put your smartphone away, do not watch TV and do not use a computer.

What is the difference between REM sleep and slow-wave sleep

The main difference between the phases of slow-wave and REM sleep of a person from each other is the difference in brain activity, which is vividly illustrated by the EEG. REM sleep is characterized by frequent eye movements, and during non-REM sleep they are practically absent. The dreams we have during REM sleep are more likely to be remembered, although studies have shown that dreams occur during both phases.

Why slow-wave sleep is better than fast sleep

Both slow-wave and REM sleep are important for the normal functioning of body systems. It is believed that the phase of non-REM sleep is more significant for recovery. By waking up a person at this time, we will deprive his brain of the opportunity to "reboot". In addition to the general poor state of health of the sleepy, impaired concentration, increased nervousness, lethargy, apathy, and irritability await. And if such deprivation of slow-wave sleep occurs regularly, there are high chances of encountering serious mental disorders. It is better to wake up in REM sleep. By the way, numerous applications for gadgets can help with this.

However, one should not think that REM sleep is useless and can be sacrificed without consequences. This phase prepares all body systems for awakening and includes the connection between the physiological processes in the brain and consciousness.

Slow-wave and REM sleep: the norm

For an average person, the norm of slow-wave sleep is 70%, and REM, respectively, 30% of the total night's rest. The total duration of sleep sufficient for recovery is 7-9hours per day.

NREM sleep should normally last about 90 minutes. It is followed by a phase of REM sleep lasting 10-20 minutes. These two stages together form a cycle that is usually repeated 5 times in a healthy person per night. The phases of non-REM and REM sleep are unevenly distributed. So, for the first time after falling asleep, the REM sleep phase lasts about 5 minutes, and closer to awakening, its duration reaches 60 minutes.

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