Sleep is a complex biological process in which your body and brain can renew themselves. When you are asleep, it may appear that the brain is not doing anything. But your brain is very active during sleep. It manages hormones, memories, and repairs the different systems.
Adults require an average of 7 to 9 hours of sleep daily. You may be in bed for eight hours and still feel very tired in the morning. This is exactly where REM sleep plays its part. This is the time when both your brain and body do some of the most crucial repairs.
Let’s look at what REM sleep actually is and how much sleep you need by age.
What is REM Sleep?
Sleep isn’t one continuous state. You go through 4 main stages in your sleep. The first three stages are non-REM sleep, which consist of light sleep (N1), deeper light sleep (N2), and deep sleep (N3).
The fourth stage is REM sleep. REM means Rapid Eye Movement and is a highly active state. This is the stage where the dream and deep reset occur.
During REM sleep:
- Your brain activity is almost similar to when you are awake
- Memory consolidation takes place
- Emotional processing happens
- The body goes into temporary muscle paralysis to prevent acting out dreams
- Dreaming is most vivid
Scientists haven’t yet fully explained why and how we dream. REM sleep typically appears about 90 minutes after you fall asleep and becomes longer in the later cycles. That’s why early morning sleep is rich in REM.
According to functional medicine, sleep is much more than just dream time. It is the time when your brain actually resets stress, processes the day’s experiences, and integrates the newly learned things.
How Much REM Sleep Do You Need?
REM sleep generally accounts for 20-25% of total sleep in most healthy adults. So, if you sleep for 8 hours, that corresponds to 1. 5 to 2 hours of REM sleep per night.
You experience your REM sleep in several cycles, beginning after 70-90 minutes of sleep. Each REM period gets longer toward the morning. So, if you cut your sleep short, it reduces REM, impacting your memory and recovery.
The amount of REM sleep you need is dependent on your age.
- Babies need approximately 50% of REM sleep, which is 14-17 hrs per night. It is extremely important for brain development.
- Children require 25-30% of REM sleep, which is equivalent to 10-13 hrs per night.
- Adults need approximately 20-25%, that is about 7-9 hrs of sleep per night.
- Older adults need 15- 20% REM Sleep, which is around 7-8 hrs. In elderly people, the amount of REM may decrease slightly with age, but it is still important for cognitive health.
Why REM Sleep Matters for Your Brain and Body
REM sleep has a positive impact on your body and mind. If you don’t get enough REM sleep, you will start experiencing sleep deprivation symptoms that include mood changes, poor focus, and tiredness. REM Sleep helps in:
- Emotional Regulation: REM sleep reduces emotional overload from stressful events. Some researchers describe. Some researchers refer REM sleep as an overnight emotional therapy. It gives your brain a chance to process your feelings without the pressures of the outside world.
- Memory and Learning: Sleep plays a very crucial role in your memory and learning process. It allows your brain to determine which experiences and information during the day should be stored and reinforced for long, term use. If you are learning new skills and are studying, then REM sleep is a must for you.
- Hormonal and Metabolic Health: REM sleep contributes to hormonal balance. It interacts with cortisol regulation, insulin sensitivity, growth hormone rhythms. Disruptions in your sleep can result in increased insulin resistance. Poor sleep can also cause weight gain and metabolic dysfunction.
- Keeps your brain healthy: REM and deep sleep N3 plays a major role in the clearing waste products that accumulate in your brain during he day. It goes a long way in supporting emotional stability and stress responses.
What Happens If You Don’t Get Enough REM Sleep?
Short-term REM deprivation can cause you brain fog, mood swings, irritability or reduced tolerance. But long-term deficiency in REM sleep can cause a variety of health issues:
- Depression
- Difficulty in controlling your emotions
- It takes longer than usual to learn new motor skills
- Brain inflammation increases
- Faster brain aging
- Metabolic disorders
- Less sleep can increase the chance of death in older adults. Every 5% drop in REM sleep raises the mortality risk by 14% in older adults.
Do you know that alcohol and some medications inhibit REM sleep. You may be sleeping, but your brain does not go through its restorative cycles. This is why, after a night of alcohol consumption, you often feel tired even though you have slept for 8 hours.
What Disrupts Your REM Sleep?
If you’re wondering how much REM sleep you need, then it is important for you to understand the factors that make your sleep worse:
Here are some of the common disrupters
- Late-night eating before bed spikes your blood sugar and insulin, which disturbs your sleep patterns. Blood sugar crashes at night may cause micro-awakenings which decreases REM sleep time.
- Alcohol initially sedates you, but it actually suppresses your REM phase during the first half of the night.
- Stress in the evening can also delay REM onset and shorten its cycles.
- Exposure to blue light at night inhibits melatonin, thereby disrupting your circadian rhythm and REM progression.
- Untreated sleep Apnea is also a factor that interrupts your REM cycles. Sleep further relaxes your throat muscles; apnea episodes make it even worse during REM.
Can You Track Your REM Sleep at Home?
The polysomnography is an in-lab sleep test, in which your doctor monitors your brain waves (EEG), eye movements (EDO), cardiopulmonary rate, and respiratory rate. This is the most reliable method for identifying REM sleep.
But many modern sleep trackers, like smartwatches and apps, claim to measure your REM sleep. However, they are not as accurate as PSG, especially when it comes to distinguishing between deep sleep and REM.
Some people use EEG headbands. They’re designed to detect brain waves at home. These are more accurate than wrist-based trackers but less convenient than wearables.
The best thing to do is to monitor your sleep time, regularity, and daily lifestyle habits. These matter much more than getting too much involved in your nightly REM percentages.
When to be Concerned About Your Sleep
It is quite normal to occasionally feel tired after a late night. However, if you are constantly feeling tired even after giving yourself plenty of time in bed, it may be a warning sign that your sleep needs a deep fix.
If you have persistent daytime tiredness despite spending 79 hours in bed, you wake up frequently, you snore loudly, and you gasp or have pauses in breathing, it might be time to seek help from a healthcare professional.
At Kairos Health & Wellness, Lola, one of our board-certified functional practitioners, goes through your apnea patterns and pinpoints the problem. Our providers give you a plan that helps you get the deep sleep that you deserve.