What is REM Sleep? Why it’s Important, How Much You Need & More

No matter who we are, where we live, or our professions are, it’s safe to say that we all agree on one thing: We need our sleep.

But Why?

One of the main reasons is a complex set of neurological processes called REM sleep. This stands for Rapid Eye Movement.

Without REM sleep, we cannot function successfully during waking hours. We become more irritable, groggy, and exhausted. Furthermore, we experience decreased concentration, memory, and cognition.

What is REM Sleep?

Sleep researcher Nathaniel Kleitman first described it in 1953. Since then, extensive research has been conducted to answer the mysteries of sleep.

As the term “rapid eye movement” suggests, the eyes tend to dart back and forth in different directions under closed eyelids. This is when dreams most often occur. Although it might seem those eye movements are due to the scanning of dream images, this has not been definitively proven. [1] Other names for REM include active sleep, desynchronized sleep, and paradoxical sleep. [2]

When Does REM Sleep Occur?

After initially falling asleep, the first cycle of Rapid Eye Movement (REM) sleep usually begins after about 60 to 90 minutes. The stages are repeated in a predictable pattern during a complete night's sleep. This pattern consists of three stages of non-REM sleep, followed by one REM sleep stage. It generally takes 90 to 120 minutes to complete one full cycle, which includes all the sleep stages.

Throughout the night, the duration of REM sleep within each cycle gradually increases. Therefore, most of the time spent in REM sleep happens during the latter half of the night.

REM vs. Non-REM Sleep

Decades of in-depth research have revealed two broad categories of sleep: Non-REM and REM sleep. [3]

Non-REM Sleep

Non-REM typically encompasses the first three sleep stages, from light sleep to deep sleep. It’s during the deep sleep stage that the body builds bone and muscle, as well as strengthens the immune system. [4]

REM Sleep

REM is the final stage of the alternating non-REM/REM sleep cycle. Typically, humans cycle through between three and five REM stages per night.

A common question asked is how long is REM cycle. Usually, REM sleep occurs within 90 minutes after falling asleep. The first stage lasts only about 10 minutes, while each of the later REM stages gets longer, and the last stage can last up to an hour.

Clinical Signs of REM Sleep

Upon entry, incredible changes occur in the brain and body. In addition to the hallmark rapid eye movement and presence of dreams, a few of these other changes are:

• Increased blood pressure and heart rate
• Increased oxygen use by the brain
• Rapid and irregular breathing
• Bodily twitching, mostly in the face, arms, and legs

One of the most amazing findings is increased brain activity that is similar to awake states. This signifies key functions and transformations that are being undertaken by our brain, neurochemistry, and neural network. All this as we sleep.

REM and Our Dreams

As the sleep cycles progress throughout the night, the REM stage, and therefore dreams, become longer. The final stage is typically the longest and can last up to an hour. [5] The final stage is typically the longest and lasts anywhere from an hour up to two hours.

In total, about two hours of sleep per night is spent on dreams. Some scientists believe that dreams represent the expression of fragmented brain activity caused by attempts by the cerebral cortex to interpret neural signals.

To prevent us from acting out dreams and becoming injured, the neurotransmitters shut down the body’s motor neurons, thus causing temporary paralysis.

Sleep Study: Role of REM sleep and Dreams

It is sometimes called “paradoxical sleep,” because it arouses some systems while paralyzing others. [7] Without this preventive safety measure in place, a condition called REM sleep disorder could occur.

Why is REM Sleep Important?

REM sleep is vital for a variety of reasons. One of its primary functions is facilitating dreaming, as most dreams occur during this stage. These dreams in REM sleep tend to be more vivid than non-REM sleep dreams.

Furthermore, REM sleep plays a crucial role in emotional processing. [8,9] The brain processes emotions during this stage, and the amygdala activation, which is responsible for emotions, is heightened. The vivid dreams experienced in REM sleep are likely involved in this emotional processing.

In addition to dreaming and emotional processing, REM sleep contributes to memory consolidation. During this stage, the brain processes newly acquired knowledge and motor skills from the previous day. It decides which memories to commit to long-term storage and which to discard. Some memory consolidation also occurs during deep sleep, a non-REM stage.

REM sleep is also believed to be important for healthy brain development. This is evident in newborns who spend much of their sleep time in REM. During infancy, species with less developed brains, such as humans and puppies, spend more time in REM sleep than species with more developed brains, like horses and birds. This suggests that REM sleep promotes brain development.

Interestingly, REM sleep may also prepare us for wakefulness. It activates our central nervous system and helps us transition from sleeping to awake. As the night advances, we tend to spend more time in REM sleep, which may explain why we are more easily awakened during this stage.

REM sleep is vital for various processes, including dreaming, emotional processing, memory consolidation, brain development, and wakefulness preparation. Its importance extends beyond just fulfilling a restful sleep and contributes to our cognitive and emotional well-being.

How Much REM Sleep Do You Need?

When you fall asleep, you first enter the Rapid Eye Movement (REM) phase, usually within 90 minutes. This stage of REM lasts for only about 10 minutes. As the night progresses, you'll go through 3-5 REM cycles, with each episode getting longer than the previous one. The final REM phase may last for roughly an hour.

For adults, it is generally recommended to spend around 20-25% of your time asleep in the REM stage, as it plays a crucial role in brain function and emotional regulation. If you manage to get 7-8 hours of sleep, you should aim for around 90 minutes of REM sleep.

It's worth noting that the amount of REM sleep needed varies depending on age. Infants may experience REM sleep for more than 50% of their total sleep time, while the average amount of REM sleep in adults decreases with age, extending through adulthood.

How Does REM Sleep Enhance Memory Performance?

REM sleep has been found to enhance working memory performance, as demonstrated in the study titled "Rapid-eye-movement-sleep (REM) associated enhancement of working memory performance after a daytime nap" [9]. The research provides evidence supporting the role of REM sleep in improving working memory tasks.

The study reveals that individuals who experience REM sleep during a daytime nap exhibit enhanced performance in working memory compared to those who do not experience REM sleep.

The findings suggest that REM sleep is crucial in consolidating and enhancing working memory abilities. During REM sleep, the brain undergoes several processes contributing to this enhancement. One such process is memory consolidation, where the brain strengthens and integrates newly acquired information into existing memory networks.

This consolidation process helps store and organize information more effectively, leading to improved working memory performance.

Additionally, REM sleep is associated with increased neural plasticity, which refers to the brain's ability to adapt and modify its connections. During this sleep stage, there is a high level of spontaneous brain activity, promoting neural network reorganization and strengthening synaptic connections related to working memory.

These changes likely facilitate the efficient retrieval and manipulation of information required for working memory tasks.

During REM sleep, people experience vivid and emotionally intense dreams that have been associated with creativity and problem-solving. These two abilities are essential components of working memory performance.

It is believed that the emotional content and spontaneous thoughts that occur during REM sleep activate various cognitive processes that encourage flexible thinking and innovative problem-solving strategies. Ultimately, this can lead to an improvement in working memory capabilities.

Understanding the mechanisms through which REM sleep positively impacts working memory can offer valuable insights for improving cognitive functioning and inform interventions for individuals with working memory deficits.

How Do I Know If I am Getting Enough REM Sleep?

You will likely be able to notice when it’s at its optimum level by how you feel during the day. The proper amount of REM sleep varies from person to person.

High-quality REM sleep lays the foundation for so many positive outcomes in daily life:

• Problem-Solving
• Positive Mood
• Memory
• Creativity
• Learn New Tasks
• Take on New Challenges
• Effective Stress Management

When we get the appropriate level of REM sleep, we awake feeling rested and can be ready to manage the demands that life throws at us effectively.

Did You Know: REM sleep should make up about 20% to 25% [10] of your total time asleep.

Read More: Circadian Rhythm and Sleep

What Happens If I Don’t Get Enough REM Sleep?

When you don't get enough REM sleep, it can affect your overall well-being. Research indicates that the deprivation of REM sleep can interfere with memory formation.

Although it is unclear whether memory problems are solely due to the absence of REM sleep or the overall disruption of sleep patterns, studies have shown that individuals who naturally do not experience REM sleep do not encounter difficulties with memory or learning.

However, it is essential to note that REM sleep deprivation can disrupt the brain's ability to generate new cells, and further research is needed to fully grasp the impacts of not getting enough REM sleep.

In addition to memory problems, missing out on REM sleep can have broader consequences for your health. Sleep deprivation, in general, has been linked to various aspects of overall well-being, including mood, immune function, and cognitive performance.

Chronic sleep deprivation, stemming from insufficient REM sleep, has been associated with an increased risk of health conditions such as depression, diabetes, depression, cardiovascular disease, and obesity. some studies have found insufficient REM sleep could lead to migraines. [11]

One aspect of cognitive function significantly affected by a lack of REM sleep is working memory. Concentrating during the day becomes more challenging without adequate sleep, and excessive daytime sleepiness may set in. Individuals who consistently sleep fewer than six hours per night, known as "short sleepers," can experience similar impairments to their working memory as those who have gone without sleep for two consecutive nights.

Since REM sleep is primarily obtained in the latter half of the night, shorter sleepers spend less time in REM sleep, compounding the effects of sleep deprivation.

Furthermore, certain medications, such as those commonly prescribed for anxiety and depression, may suppress REM sleep, further exacerbating the potential consequences of insufficient REM sleep.

Sleep Disorders Associated with REM Sleep

Several sleep disorders are closely associated with REM (rapid eye movement) sleep. These include REM sleep behavior disorder (RBD), narcolepsy, nightmare disorder, and sleep apnea.

REM Sleep Behavior Disorder (RBD

It's a condition where individuals do not experience the usual muscle paralysis during REM sleep. As a result, they may physically act out their dreams by shouting, kicking, punching, or jerking, which can potentially lead to self-injury or harm to their sleep partner.

RBD is caused by a malfunction in the brainstem that regulates REM sleep. It is worth noting that RBD is often considered a precursor to the development of neurodegenerative diseases.

Narcolepsy

People with narcolepsy may experience episodes of cataplexy, which involves a sudden loss of muscle tone. This occurs because individuals with narcolepsy can fall into REM sleep instantly, even when they are awake.

Other symptoms of narcolepsy include excessive daytime sleepiness, disrupted REM sleep patterns, and hypnagogic hallucinations - dream-like experiences that occur just before falling asleep. The loss of orexin neurons in the hypothalamus is considered a potential cause of narcolepsy.

Nightmare Disorder

People who suffer from Nightmare Disorder experience recurring and distressing nightmares during their Rapid Eye Movement (REM) sleep. Stressful situations, childhood trauma, or other frightening experiences can trigger this disorder.

Nightmares typically occur during REM sleep and can disrupt overall sleep quality.

Obstructive Sleep Apnea (OSA) and Central Sleep Apnea (CSA)

Two types of sleep apnea can also affect REM sleep. Sleep apnea involves repeated pauses in breathing during sleep. Although these lapses in breathing may happen across different sleep stages, they can impact the amount of time spent in REM sleep.

Individuals with sleep apnea often move to a lighter sleep stage to maintain breathing when apnea episodes occur during REM sleep. As a result, they may have reduced REM sleep and experience excessive daytime sleepiness.

How to Get More REM Sleep

Everyone's sleep is different. You don't need to be a scientist to understand the importance of this sleep stage. If you're looking for ways to get more REM sleep, you'll need to take a look at a previous article on how to get more REM sleep. When reviewing the list, you might have to try more than one to see which one works best for you.

When You Should Talk to Your Doctor About Sleep Issues

It is important to consult your sleep issues with a medical professional if you experience symptoms of sleep deprivation or suspect that you may have a sleep condition such as nightmare disorder or REM sleep behavior disorder.

Consulting your doctor will allow them to effectively determine the causes of your sleep problems and work with you to create an appropriate treatment plan to enhance your sleep quality.

Final Thoughts

REM sleep is necessary for good health. Chronic sleep deprivation can negatively impact your quality of life, but there are ways to improve your sleep. If lifestyle changes don't help, talk to your doctor about medications that might be helpful.

So, the next time you lay your head down for a good night’s dream time, remember that it’s definitely not a waste!

Think of sleep as a time for creativity, free associations, problem-solving, and actively learning new things…storing them in your long-term memory for future use. As you awaken feeling bright and rested, you know that you can meet your challenges, have fun, and be productive. Most of all, you can simply have a fabulous day.