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Blog > What Is REM Sleep and How Does It Improve Your Health? 2025
If you have ever woken up tired after slumbering for hours, there’s a big chance you did not experience REM phase — more commonly known as deep sleep. Studies show dire consequences of skimping on getting proper deep sleep on overall health.
You’ll only understand why you need REM sleep, once you know how it impacts your bodily functions.
This article will help clarify the concept of REM and its multiple benefits. We will also explore how you can realize if you’re in critical need of catching up on some z’s and tips to improve your deep sleep phase.
The human body undergoes a sleep cycle with different stages, including NREM and REM. Interestingly, the sleep cycle in adults and babies is slightly different — mainly due to duration variations.
During NREM you don’t usually experience dreaming. It consists of three stages namely N1, N2, and N3. The first stage lasts for 5 to 10 minutes, the second for 10 to 25 minutes, and the last continues for 20 to 40 minutes.
REM is a phase which a person enters after 90 minutes of falling asleep. The first episode lasts for 10 minutes, and the next occurence becomes longer as the night goes on.
So, on average, how much REM sleep does a person need every day?
Generally, REM sleep accounts for more than 50% of the cycle in babies, whereas 20 to 25% of the adult sleep cycle.
As mentioned earlier, when it comes to snoozing, you experience various stages — whether you’re enjoying a nap or a solid eight-hour rest. After passing through each phase, consequently, the brain may or may not reach REM.
Adults experience a total of five sleep stages from Stage 1 to REM. The first 90 to 110 minutes of slumber concludes one cycle. Each phase may last from 5 to 15 minutes and has a specific purpose for our body.
Adult Sleep Cycle
Infants too experience REM sleep (yes, hard to believe, since they are practically up all night). However, their sleep cycle is short since deep snooze occurs at a different stage.
Baby’s sleep cycle
Stage 1: The first stage is when the baby begins to fall asleep.
Stage 2: The second stage is where light sleep starts; the infant’s legs or arms may twitch occasionally. The baby’s body is preparing itself for deep sleep.
Stage 3: The third stage is REM sleep or the rapid eye movement. Your little one is deeply asleep (thankfully) and off to dreamland!
Stage 4: The fourth stage is where the baby begins to leave the deep sleep stage and may wake up.
As you can see, the main difference between both the REM sleep stages is that infants fall asleep faster than adults. Lucky them!
Now let’s find out what exactly is REM sleep.
The term REM stands for Rapid Eye Movement and is the final stage of the sleep cycle. During this phase, your body systems — specifically breathing and brain, become more rapid and active, even though your muscles are relaxed. If you wake up during REM sleep, you’ll feel tired and achy.
As soon as you enter the first 90 minutes of snooze, that’s when you experience REM, and it reoccurs several times every night.
Did you know that REM is also known as “paradoxical sleep”?
That’s because even though you’re sound asleep (it’s difficult to wake up instantly), an Electroencephalogram (EEG) shows rapid activity peaks in the graph. In short, the activity is quite similar to when you’re actually awake.
Let’s take a brief look at how REM occurs.
The human brain is responsible for helping you fall into deep sleep. However, it is not a simple process. Once you understand the basics of REM, you’d become more aware of how you are resting every night.
Brain parts involved in REM sleep
The following table displays various regions showing vigorous action during the REM phase.
|
Region |
Activity during deep sleep |
| Brain stem |
|
| Thalamus | Uses sensory info from our memory to form dreams |
|
Pineal gland |
Releases sleep-inducing hormone |
|
Amygdala |
Processes feelings during deep sleep |
|
Hypothalamus |
Adjusts circadian rhythm |
As soon as the hypothalamus senses darkness approaching, it works with other brainstem regions such as pons, midbrain, and medulla oblongata to start the sleep-wake cycle. Alongside, the pineal gland releases a sleep hormone that makes you groggy.
After a while, thalamus and amygdala activate to retrieve memories and assess emotions to form dreams.
The brain’s chemical activity is fascinating as it begins the sleep-wake cycle. Let’s see which hormones or neurotransmitters are discharged during snooze.
Neurotransmitters are chemicals released by the brain to carry messages from one point to another. These chemical substances are released before any action is performed in your body. Even during sleep, neurotransmitters play a vital role in processing thoughts, adjusting your sleep cycle, and helping you sleep better.
If you are curious about how your sleep is regulated, this brief overview of neurotransmitters will clear your mind.
| Neurotransmitter |
Contribution to Deep Sleep |
| Acetylcholine |
|
| Serotonin |
|
| Dopamine |
|
| Histamine |
|
| Norepinephrine |
|
| Adenosine |
|
| GABA (Gamma Aminobutyric Acid) |
|
As soon as you drift off to slumberland and reach the REM phase, you may or may not start dreaming.
Usually, a person dreams for around two hours a night. The process begins when pons releases chemicals to render your body paralyzed during deep sleep. This is good for you — because if your muscles are active, you might start acting out the dreams. It could be dangerous for you and the people around you.
Many people forget what they were dreaming about as soon as they wake up. But others may remember even if they are woken up mid-snooze.
Researchers agree that the last thoughts you have before going to bed, and the information your brain has retained over the years, can be used to create dreams.
Dreams occur in REM phase
Deep sleep in infants differs in terms of cycle and stage durations from that of adults. Babies enjoy a much lighter slumber compared to us. Unlike adults, a baby’s sleep is scattered in episodes during the day.
For example, adults usually snooze for a solid eight hours. But the little ones wake up frequently while slumbering, so their cycle is divided during the day.
As most of the baby’s time is spent in active snooze rather than deep sleep, their cycle length is quite different from adults.
Newborns rest for 16 hours, which gradually shortens as they grow older. At two months, the cycle would last for 15 hours, and by the time they reach three months age, they’d need around 12 hours of sleep.
You might wonder how much deep sleep does a child need?
At least 50% of the baby’s sleep cycle should be REM. But in infants, it is commonly known as quiet sleep.
Quiet sleep is basically an infant’s version of REM. During the late half of the cycle, babies fall into the quiet sleep time — the breathing slows down, there are no movements and no eyelid flutters.
This could mean two things. Either your little bundle of joy is about to wake up OR go back to active sleep.
But remember — it takes at least six months for babies to enjoy straight sleep like adults. Till then, you better be prepared for wakefulness episodes during the night!
YES.
Interestingly, scientists have revealed that babies start dreaming when they are still in their mommy’s womb!
Unfortunately, they are still trying to figure out exactly what babies are dreaming about. Let’s just say, unicorns and tasty cupcakes!
Have you ever seen a baby smile while snoozing (and you just wanted to wake them up and tell you what it was all about)?
Many mothers believe it has something to do with neonatal gas. However, experts discovered it is just a spontaneous REM-related occurrence and is related to increased drowsiness.
In other words, a sleepy smiling baby means you have a few more relaxing minutes left to enjoy!
A complete sleep cycle is necessary to get a rejuvenating and energizing night’s rest. REM sleep offers numerous benefits to your health, some of which are discussed below.
REM improves memory
REM sleep improves your ability to recall facts from your memory — specially if you’ve had excellent sleep patterns when you were an adolescent.
Potkin and Bunney researched in 2012 on children aged between 10 to 14 years to assess the impact of REM on declarative (fact recalling) memory. The subjects were divided into two groups – one slept well while the other didn’t.
Researchers found that the former group had 20% increased memory recalling ability than the other. This indicated the recommended amount of deep sleep is crucial for enhanced memory consolidation.
Because seniors do not get enough REM slumber, you can see its impact on memory retention. In the long run, consistent lack of deep sleep may even lead to dementia.
Maintaining proper heart health is not just a concern for older people anymore. Anyone is at risk of developing a cardiovascular problem — specifically those who skimp on REM sleep.
If you don’t get a solid deep slumber for a few hours, the brain releases chemicals to prevent the dangers of continuously low blood pressure and heart rate. And thus, the system gets messed up, and you start waking up with high blood pressure.
According to a 2016 study published in the Journal of Brazilian Society of Cardiology, up to 72 hours of REM sleep deficit results in increasingly high blood pressure, causing ventricular arrhythmia or inflammation.
Some people are afraid lack of deep sleep might cause death. Well, now imagine the risks to your heart health if you miss out on REM for only a week!
During the day, the mind gets filled up with useful information as well as garbage.
Yeah, you read that right.
Think of the brain as your electronic device’s memory. Now and then, you need to get rid of the accumulated cache (commonly called junk) to free up the space for new information and delete the hazardous files.
Similarly, your brain refreshes when you are catching your z’s. Various chemicals are discharged to remove the toxins that accumulate while you were awake. After removing the cellular gunk, your brain is ready to take up new info the next day and work normally again.
Deep sleep prevents psychological disorders
Have you noticed when you don’t sleep well, you wake up cranky and moody — possibly with a horrible headache?
REM slumber is directly associated with moods and mental health. Studies have shown sleep deprivation leading to depression, anxiety, bipolar disorder, sleep and schizophrenia in almost 90% of the cases.
After experimenting, researchers also found that only one night’s lack of deep sleep can result in a dramatic mood change in 60% of the patients. In some instances, they also found a relation between depression development and short REM cycle duration.
Most doctors consider a decrease in deep sleep as one of the symptoms of mental illnesses. Hence, they try alleviating it to treat the psychological problem.
So, to avoid any psychiatric illness, put down your cell phone at night, switch off Netflix and prepare yourself for a healthy night’s rest.
Besides affecting your mental health, ignoring REM can further turn really nasty and cause lasting neurological diseases, such as Alzheimer’s, Parkinson’s, dementia, and Huntington’s disease.
More than half of the elderly folk aged 60 above are prone to neurodegenerative disorders — with one of the main reason or symptom being lack of deep sleep.
20 to 50% of the patients develop severe sleep disturbance due to Alzheimer’s, which may worsen if the condition debilitates. Most people with parkinsons are affected by REM behavior disorder — a disease in which a person acts out his/her dreams.
Cognitive behavioral therapy, catching up on missed slumber overnight, use of antidepressants and chronotherapy (light exposure to adjust melatonin release) techniques have shown dramatic improvements in treating the onset of these conditions.
Neurological problems can occur because of consistent REM deficit. In other instances, sleeplessness might become a symptom of such diseases. Bottomline, treating your snooze issue can reduce the risk of developing long-term neurodegenerative disorders.
A relaxing night’s sleep is exactly what you need to refresh your body systems and give it some time to rest. While you’re enjoying a deep slumber, the digestive system gets a chance to slow down for a bit and stop with all the hard work — like breaking down food and producing energy.
If you don’t sleep well at night, the stomach won’t be able to replenish the lost energy, and the digestion process would not be efficient. So, metabolic activity will be negatively impacted.
Additionally, during REM, the blood circulation improves to your main organs including lungs, kidneys, stomach, heart, and even muscles. Thus, when you wake up, you feel rejuvenated and energized.
In short, lack of REM could be bad for you. If you’re interested in learning more about how REM affects your health, check out this highly informative TED talk by Dan Gartenberg.
Okay. So now that you know why REM sleep is important for you, you’ve been forcing yourself to sleep for a solid eight hours every night.
But still, you’re unable to get anywhere near the last phase
If this sounds familiar, don’t worry. Following are some useful tips to improve your REM sleep experience naturally by reducing late-night interruptions.
REM deficit is dangerous for health
Loss of REM sleep impacts your health big time. That’s right! Sleep deprivation not only leads to sleepiness, but it can also wreak havoc to your health. One of the most common health issues that you may experience due to losing out on sleep is REM Sleep Behavior Disorder.
When you suffer from REM Sleep Behavior Disorder, you unconsciously act out your dreams in a violent manner which may not only be dangerous to you but to your bed partner as well.
Be wary of the following symptoms, so you know when to catch up on your z’s.
In conclusion, getting an appropriate amount of deep slumber every night is crucial for your overall well-being. The better rested you are, the more properly you’ll perform at work and would enjoy a happier life.
Hopefully, this in-depth blog exploring the various benefits of REM sleep helped you understand exactly why you should never compromise your snooze quality.
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Meet The Author:
Shanir Kol
Shanir Kol, founder and CEO of SleePare, pioneered the “Try and Buy” model in eCommerce, enhancing mattress shopping by combining in-store trials with online purchases. Launching in 1999, his company focuses on customer satisfaction and eco-friendly practices, aiming to minimize mattress waste and expand sustainably.