What is REM sleep? – Sleep Guide Part 4

One of the most pressing problems of modern society is sleep deprivation and the drastic decline in sleep quality. We might be getting enough sleep, yet we still wake up tired and exhausted the next day. This is because the sleep we get is not quality sleep, as it's not a passive state but an active, multi-stage biological process.

One of the most important stages of this process is the REM (Rapid Eye Movement) phase, when the brain enters an almost "awake" state while the body is completely relaxed. During this period, memories are processed, learning is reinforced, and the nervous system regenerates.

To understand the processes occurring in our bodies, we sought answers to the following questions:

• What exactly is REM sleep?

• How does it differ from deep sleep?

• What does REM sleep mean for our body, memory, and emotional regulation?

• How much REM sleep is necessary to stay mentally fresh and cope successfully with daily challenges?

What does REM sleep mean in practice?

REM sleep is not just about dreaming. Although many people think of it this way, during this time the brain works very actively: it processes memories and helps with learning.

This sleep stage was discovered in 1953 when researchers (Eugene Aserinsky and Nathaniel Kleitman) noticed rapid eye movements under closed eyelids during sleep. This is where it got its name: "Rapid Eye Movement."

The uniqueness of the REM phase is that the brain's activity is almost like being awake, while the body is in a deep sleep. This is why it is also called "paradoxical sleep."

Meanwhile, rapid eye movement and brain processes are closely linked: they are not only connected to dreams but also help process information.

Interestingly, during this time, the body is almost completely motionless. The muscles temporarily "switch off" – this is called REM atonia. This is a protective mechanism that prevents us from "acting out" our dreams, thus avoiding injuries. Only vital muscles, such as those responsible for breathing, remain active.

Sleep consists of two main stages, both responsible for different functions:

● NREM sleep (non-REM)

This makes up most of sleep (approx. 75–80%). During this time, the body regenerates:

• we relax and then fall into a deep sleep,

• the body "repairs" tissues,

• the immune system strengthens,

• physical fatigue decreases.

● REM sleep

This is the time for mental and emotional processing:

• the brain is very active,

• it processes experiences,

• it aids learning and memory,

• it "organizes" information.

The two phases together ensure complete regeneration. If these phases are present in the right proportion, a short-term lack of REM sleep will make us more irritable, and concentration and problem-solving abilities will deteriorate. In the long run, it can cause more serious problems: memory impairment, increased stress, and even a higher risk of illness.

What happens in your body during the REM stage?

Neural activity and cognitive organization

During REM sleep, our body and brain function in a very special way. Although we appear calm externally, the brain is particularly active: it processes the day's events, organizes memories, and "sorts out" what is important and what can be forgotten. This is a kind of mental spring cleaning that helps with learning and emotional balance. Meanwhile, strong emotions also "calm down," which is why REM sleep is considered a form of nocturnal emotional processing.

Hormonal regulation and neurochemical environment

A lot also happens on a hormonal level: sleep-promoting melatonin and awakening-responsible cortisol work in harmony, while the brain enters a state where the level of stress-related substances decreases. This allows us to process experiences calmly, in a "safe environment."

Presence of bodily tension and autonomic instability

Meanwhile, the body is almost completely relaxed, and the muscles switch off, but internal functions are not uniform: heart rate and breathing can become more variable. Furthermore, the body's thermoregulation is weaker at this time, making us particularly sensitive to the environment. If it's too hot or cold, or the mattress is not adequately ventilated, we can easily wake up – thus interrupting this important sleep stage.

How much REM sleep is needed for healthy sleep?

Restful sleep depends not only on the number of hours spent sleeping but also on how much time we spend in the REM phase. A night consists of several cycles of approximately 90 minutes each: at the beginning, the body regenerates, but later, the REM stages become progressively longer, which is why we dream most towards dawn.

Ideally, 20–25% of sleep for adults is REM, which translates to approximately 1.5–2 hours for an 8-hour sleep. However, if we shorten our sleep – for example, by going to bed late and waking up early – we lose the most from this crucial stage. The effects are quickly noticeable: we become more tired, irritable, and our concentration and thinking abilities deteriorate.

Children need even more (30-50%) REM sleep, as this supports brain development and learning. Overall, therefore, it's not just how much we sleep that matters, but also that we get enough time in this key sleep phase.

The optimal amount of REM is therefore not a universal number but shows strong age-specific characteristics.

What can disrupt the REM phase?

REM sleep is the most intense, yet also the most fragile sleep stage. Its occurrence requires perfect neurochemical and physical harmony between the brain and the body. As soon as this balance is disrupted, the REM phase shortens, becomes fragmented, or may even be completely absent.

Mental and physical causes

REM sleep is a very sensitive state and can easily be disturbed if the body or brain is not "in balance." One of the most common causes is stress: if we cannot calm down by evening, the body remains in a state of readiness and cannot transition into restful sleep. Similarly, alcohol, late-night coffee, or certain medications exacerbate the situation because they disrupt the natural rhythm of sleep.

Health and environmental issues

Health problems can also play a role, such as sleep apnea, where breathing repeatedly stops during the night, disrupting sleep continuously and preventing the REM phase from occurring.

The environment also plays a key role: light, noise, or an uncomfortable mattress can all prevent us from reaching deep enough sleep. Since the body is particularly sensitive at this time, even minor disturbances can wake us up or interrupt this important stage.

CHOOSE A COMFORTABLE MATTRESS TO ENSURE YOUR NIGHTS ARE FILLED WITH COMPLETE PEACE!

We can't dream enough – What should we do?

If someone experiences insufficient REM sleep and feels tired and exhausted as a result, the solution is not solely to be found in sleeping pills. The most important goal is to restore the body's internal rhythm, not merely to increase the time spent sleeping.

Solutions for improving sleep:

● Regular sleep routine: Going to bed and waking up at the same time helps stabilize the body's internal clock, making it easier to reach deeper sleep phases.

● Avoid screens in the evening: The light from digital devices inhibits the production of sleep-promoting hormones, so it's advisable to avoid them at least 1-2 hours before bedtime.

● Calm evening routine: Relaxation, reading, or slow breathing supports the nervous system in calming down, which promotes restful sleep.

● Mindful eating: Heavy, fatty foods, alcohol, and late caffeine consumption can impair sleep quality, so it is advisable to avoid them in the evening.

● Appropriate temperature: A cooler bedroom, between 16–19 °C, helps undisturbed sleep, as the body reacts more sensitively to environmental temperature at this time.

The role of physical comfort and mattresses

Sleep is not just a mental process, but a very physical one: if the body does not receive adequate support, the brain cannot achieve deep, restful sleep. An uncomfortable mattress does not relieve pressure points (such as the shoulders or hips), which causes tossing and turning, and small awakenings interrupt sleep cycles, thereby damaging deep sleep and the REM phase.

A good mattress, on the other hand, distributes body weight evenly, maintains the natural alignment of the spine, and helps the body to relax completely. Research suggests that medium-firm, multi-zone mattresses are the most ideal because they provide both stable support and comfort.

ERGONOMIC MATTRESSES ARE DESIGNED TO BE COMPLETELY TAILORED TO OUR BODIES.

The htemperature is also crucial: during sleep, the body becomes more sensitive, so it is important that the mattress is well-ventilated and does not retain heat. If the sleeping surface is too hot or too cold, it can easily interrupt sleep.

Recommended mattresses from Yatas Bedding's selection

The following models particularly support restful sleep and undisturbed REM phases:

• Adapt Rest mattress
  Thanks to its hybrid construction, it provides both stable support and comfort. A good choice for those who want to reduce tossing and turning at night.

• Zero Gravity Latex mattress
  It perfectly conforms to the body's contours while being well-ventilated, helping to avoid overheating – ideal for calm, uninterrupted sleep.

• Natura Rest mattress
  A premium solution that offers outstanding ergonomics and long-term comfort, especially for sensitive sleepers.

• Athletic mattress
  A well-ventilated, stable-base mattress that can be a good choice for everyday use.

In many cases, poor sleep is not caused by an illness but by a worn-out or unsuitable mattress. Replacing an 8–10-year-old mattress can, by itself, lead to significant improvement: the number of nighttime awakenings decreases, and the proportion of deep and REM sleep increases.

Choosing the right mattress is therefore not a luxury but a fundamental prerequisite for restful sleep – and, in the long run, for improved well-being.

VISIT ONE OF OUR STORES, AND WE WILL HELP YOU CHOOSE THE IDEAL MATTRESS!