REM sleep vs. deep sleep (and how much do you need of both?)
Clinically reviewed by Dr. Chris Mosunic, PhD, RD, CDCES, MBA
Learn the distinctions between REM vs. deep sleep stages and how they benefit overall health. Plus, how much REM and deep sleep you really need.
Sleep consists of stages, and two of the best known are rapid eye movement (REM) sleep and deep sleep. While REM sleep is often associated with the mind and cognitive functions, deep sleep is all about physical restoration and health. Both are essential for overall health and wellbeing, and getting a balanced cycle of REM and deep sleep is key to waking up feeling refreshed and ready to tackle the day.
REM vs. deep sleep
Our sleep is divided into several cycles, each consisting of different stages, including REM sleep and deep sleep. Understanding what happens during each stage can help us appreciate why sleep is so important for our health.
What is REM sleep? 5 benefits of REM sleep
REM sleep is a fascinating stage of our sleep cycle. It's called REM, because, during this stage, our eyes move rapidly in various directions, even though they're closed. This stage is strongly associated with vivid dreams. During REM sleep, our brain activity spikes, resembling activity patterns from when we are awake. Interestingly, REM sleep increases in duration in the latter half of the night, which is why we often wake up from a dream in the morning hours.
REM sleep is particularly important because of the benefits it brings to our cognitive functions.
Enhances learning and memory
Supports emotional regulation
Cultivates creativity and problem-solving
Contributes to brain development
Improves mental health
What is deep sleep? 6 benefits of deep sleep
Deep sleep — also known as slow-wave sleep — is the stage of sleep when our brain waves slow down significantly. This is the most restorative phase of sleep, ensuring we wake up feeling refreshed and rejuvenated. Deep sleep typically occurs in longer periods during the first half of the night.
Deep sleep is associated with essential benefits to our physical wellbeing.
Promotes physical healing and repair
Boosts immune system functionality
Facilitates growth and development
Enhances memory consolidation
Regulates hormones
Supports brain health
Is REM or deep sleep better?
Neither REM nor deep sleep are better than the other. REM and deep sleep complement each other, with REM sleep supporting cognitive and emotional health and deep sleep focusing on physical restoration. A balanced cycle between REM and deep sleep is vital for overall health, contributing to everything from mood regulation and cognitive function to physical health and disease prevention.
Understanding the distinct roles of REM and deep sleep showcases why a good night's sleep is more than just quantity. A good night’s sleep is about quality and the balance of these different stages. Ensuring we get adequate amounts of both types of sleep can make a significant difference in our overall health, wellbeing, and daily functioning.
How much REM and deep sleep do you need?
These percentages can vary depending on your age, lifestyle, and overall health. For example, children and adolescents typically need more REM and deep sleep to support their growth and development.
REM sleep: Adults should aim for about 20–25% of their sleep to be REM sleep. This translates to roughly 1.5 to 2 hours per night if you're getting the recommended 7–9 hours of total sleep.
Deep sleep: For deep sleep, adults typically need about 13–23% of their sleep in this stage, which equates to about 1 to 2 hours per night in a 7–9 hour sleep period.
Do you dream during deep sleep?
Dreaming plays a role in our mental health and emotional processing. REM sleep dreams are more vivid and have been more extensively studied for their role in learning, memory, and emotional regulation, but the full importance of dreaming during deep sleep is still a subject of ongoing research.
REM sleep and dreaming: REM sleep is most commonly associated with vivid dreams. The brain's activity during REM is similar to when we're awake, facilitating intense, often memorable dreams. This stage is important for processing emotions and experiences through dreams.
Deep sleep and dreaming: While deep sleep is primarily for physical restoration, it's a myth that we don't dream at all during this stage. Dreams can occur during deep sleep, but they are typically less vivid and harder to remember.
Dream myths and misconceptions: true or false?
Myth: You only dream during REM sleep.
Reality: While most dreaming occurs during REM, it's possible to dream during all sleep stages, including deep sleep.
Myth: Dreams in deep sleep are just like those in REM sleep.
Reality: Dreams during deep sleep are usually less vivid and less likely to be remembered than those during REM sleep.
Myth: Not dreaming means you're not getting deep or REM sleep.
Reality: You might not always remember your dreams, but that doesn't mean you're not experiencing them or going through the essential sleep stages.
REM sleep vs deep sleep FAQs
Can you influence the amount of REM vs. deep sleep you get?
Yes, you can influence your sleep stages through your lifestyle choices and sleep habits. Creating a consistent sleep routine, optimizing your sleep environment, managing stress, and avoiding stimulants like caffeine and electronics before bed can help increase the quality of your sleep. This could also potentially increase your REM and deep sleep stages. Exercise and diet also play roles in how well you cycle through the various stages of sleep.
Why might someone lack deep sleep or REM sleep, and what can be done?
Lack of deep sleep or REM sleep can be due to various factors, including stress, aging, lifestyle habits, and medical conditions. Taking steps to improve your sleep hygiene — maintaining a consistent sleep schedule, creating a restful sleeping environment, and avoiding stimulants close to bedtime — can help. If sleep issues persist, consulting a healthcare provider is advisable, as they can help identify and treat any underlying conditions.
Does the percentage of deep sleep needed change as you age?
Yes, the percentage of deep sleep you need does change with age. Infants and children require more deep sleep for growth and development, while adults might see a decrease in deep sleep as they age. However, deep sleep remains essential throughout life for physical restoration and brain health. Even though older adults may get less deep sleep, ensuring quality sleep is vital for wellbeing.
What are the signs of not getting enough REM or deep sleep?
Signs you are not getting enough REM or deep sleep include daytime fatigue, mood swings, difficulty concentrating, memory issues, and a general feeling of not being well-rested. Over time, insufficient REM or deep sleep can impact your overall health, increasing your risk of chronic conditions, affecting mental health, and diminishing immune function.
How do sleep stages affect your ability to wake up feeling refreshed?
Each sleep stage plays a critical role in ensuring you wake up feeling refreshed. Deep sleep helps with physical restoration and energy replenishment, while REM sleep is important for cognitive functions and emotional balance. A healthy balance between REM and deep sleep, along with uninterrupted sleep cycles, contributes to waking up feeling rested and alert. If these stages are cut short or disrupted, you might wake up feeling tired — even after a full night's sleep.
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