Home / Blog February 23, 2024

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Is There A Difference Between Core Sleep And Deep Sleep?

Ever wondered about the difference between core sleep and deep sleep? In this blog, we discuss the fundamental differences between these two rest states and offer tips for ensuring your ZzZs are top-notch.



Core sleep includes REM (Rapid Eye Movement) and deep sleep.

Deep sleep helps with physical recovery, immune function, and memory consolidation.

REM sleep is associated with vivid dreaming and integrating emotional experiences. 

Did you know?
Babies spend about 50% of their sleep time in REM (Rapid Eye Movement) sleep, as it is crucial for their brain development and learning!

Have you ever wondered what goes on in your body while you’re snoozing away each night? It’s a bit like a hidden adventure, with your brain and body embarking on a journey through different stages of sleep. But here’s the question of the hour: is there a difference between core sleep and deep sleep? In this blog, we discuss the answers to this curious query – and whether or not the distinction matters.

Let’s dive in!

What Is Core Sleep?

Core sleep is the critical amount of uninterrupted sleep needed for essential thinking and physical health. It happens in one long stretch during the night, including deep sleep and REM (Rapid Eye Movement) sleep, which are important for restoring your body and mind.

We often talk about core sleep when discussing sleep patterns and how to improve sleep quality. Unlike naps or polyphasic sleep, where sleep is divided into shorter periods, core sleep is one continuous chunk, usually lasting 6 to 8 hours for adults.

During core sleep, your body does important things like consolidating memories, repairing tissues, regulating hormones, and boosting your immune system. If you don’t get enough core sleep your thinking, mood, immune system, and overall health are at risk of being affected. So, ensuring you get enough uninterrupted core sleep is crucial for staying healthy and feeling your best when awake.

Next, let’s take a closer look at one element of core sleep: deep sleep.

Is REM Or Deep Sleep More Important?

What Is Deep Sleep?

Deep sleep, also known as slow-wave sleep (SWS) or stage 3 sleep, is a phase of sleep characterized by slow brain waves, a reduced heart rate, and decreased muscle activity. It is one of the four stages of non-REM (rapid eye movement) sleep, which occurs in cycles throughout the night.

During deep sleep, the body undergoes several vital processes, including:

1. Tissue growth and repair: Deep sleep is essential for the body to repair muscles, tissues, and cells. Human Growth Hormone (HGH) is released during this stage, facilitating the repair and regeneration of tissues.

2. Immune function: Deep sleep plays a crucial role in strengthening the immune system. It allows the body to produce cytokines, proteins that help combat infections, inflammation, and stress.

3. Memory consolidation: Deep sleep is important for consolidating memories and integrating new information into long-term memory. It helps improve cognitive function, learning, and problem-solving abilities

4. Hormone regulation: Deep sleep regulates the release of various hormones, including cortisol (stress hormone), insulin (regulates blood sugar), and leptin (regulates appetite). Disruption of deep sleep can lead to hormonal imbalances and metabolic issues.

Because of all these factors and more, deep sleep is the most restorative stage of sleep, and people who consistently get enough deep sleep tend to experience better physical and mental health outcomes.

Next, let’s compare deep sleep and REM sleep, both distinct parts of the sleep cycle.

Is REM Or Deep Sleep More Important?

REM and deep sleep are equally important because each brings something different to the table. Let’s look at the role of REM sleep and how it matches up to to the functions of deep sleep

REM sleep is associated with vivid dreaming and processing emotional experiences. It is crucial for brain development, especially in infants and children, as it supports learning and creativity.

A healthy sleep pattern includes cycling through REM and deep sleep stages multiple times at night. Disruption of either REM or deep sleep negatively affects various aspects of health, like cognitive function, emotional regulation, immune function, and physical recovery. Because of this, neither stage is deemed more important than the other, as they both contribute to overall sleep quality and health.

Next, let’s compare deep sleep and light sleep and see how these differ.

Differences Between Light Sleep And Deep Sleep

Light sleep is a stage of sleep where your body and brain are starting to relax, but you’re still somewhat aware of your surroundings. This stage is essential for transitioning between wakefulness and deeper sleep stages.

Here is a table summarizing the key differences between deep sleep and light sleep:

Light and deep sleep are essential components of a healthy sleep cycle, each serving different functions to promote physical and mental well-being. Achieving a balance between these stages is important for overall sleep quality and restorative benefits.

So next, let’s focus on how much deep sleep you need every night to maximize your sleep quality.

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How Much Deep Sleep Do You Need?

The amount of deep sleep needed each night varies depending on age, personal differences, and overall health. Generally, adults aim for about 20 - 25% of their total sleep time to be spent in deep sleep. For most people, this equates to 1.5 to 2 hours of deep sleep per night.

The distribution of sleep stages varies throughout the night, with more deep sleep occurring earlier in the sleep cycle. Factors like sleep quality, sleep disorders, stress levels, and lifestyle factors influence the total amount of deep sleep.

In the next section, let’s look at some practical tips on ensuring you get deeper sleep every night.

Tips On How To Have Deep Sleep

Here are some practical strategies to help you sleep more deeply every night:

1. Stick to a Consistent Sleep Schedule: Try to go to bed and wake up at the same time every day, even on weekends. This helps regulate your body’s internal clock, making it easier to fall asleep and wake up naturally.

2. Create a Relaxing Bedtime Routine: Establish a calming pre-sleep routine to signal to your body that it’s time to wind down. This might include activities like reading, taking a warm bath, practicing relaxation techniques like deep breathing or meditation, or listening to soothing music.

3. Optimize Your Sleep Environment: Make sure your bedroom is conducive to sleep by keeping it dark, quiet, and cool. Use blackout curtains, white noise machines, or earplugs to block out any disturbances that disrupt your sleep.

4. Limit Exposure to Screens Before Bed: The blue light emitted by screens (like smartphones, tablets, and computers) interferes with your body’s production of melatonin, a hormone that regulates sleep-wake cycles. Aim to reduce screen time at least an hour before bedtime to promote better sleep.

5. Consider Your Diet: Steer clear of caffeine and nicotine close to bedtime, as they interfere with your ability to fall asleep and stay asleep. Additionally, be mindful of heavy meals, alcohol, and spicy foods, which disrupt sleep or cause discomfort.

6. Exercise Regularly: Engage in regular physical activity, but try to avoid vigorous exercise close to bedtime, as it energizes you and makes it harder to fall asleep. Aim to finish your workout at least two hours before bedtime.

7. Manage Stress and Anxiety: Practice stress-reduction techniques like mindfulness meditation, progressive muscle relaxation, or journaling to help calm your mind and promote relaxation before bed. Sleep aids like weighted blankets also help in calming the nervous system. The gentle pressure of a blanket like our Cotton Napper promotes relaxation, naturally encouraging you to sleep deeply.

If, after trying these tips, you find yourself still waking up feeling groggy, then you may not be getting enough deep sleep.

Next, let’s look at some tell-tale signs that your sleep-related challenges warrant a medical visit to your doctor.

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When To See A Doctor

Here are some red flags that indicate you should discuss your sleep troubles with a medical professional.

1. Chronic Insomnia: If you have trouble falling asleep, staying asleep, or waking up too early for at least three nights a week for several months, it could be a sign of chronic insomnia.

2. Excessive Daytime Sleepiness: If you feel excessively sleepy during the day, despite spending enough time in bed at night, it could be a sign of underlying sleep disorders like sleep apnea, narcolepsy, or restless legs syndrome. This is also true if you frequently feel tired, fatigued, or lacking in energy despite getting what you believe to be sufficient sleep.

3. Loud or Persistent Snoring: Especially when accompanied by pauses in breathing or gasping for air, this may be a sign of obstructive sleep apnea, a serious sleep disorder that warrants medical attention.

4. Difficulty Breathing During Sleep: If you experience choking, gasping, or difficulty breathing during sleep, it could be a sign of sleep-related breathing disorders.

5. Frequent Nightmares or Night Terrors: If you experience frequent nightmares, night terrors, or other disturbing sleep-related behaviors that disrupt your sleep, see a sleep specialist.

6. Shift Work Sleep Disorder: If you work irregular or rotating shifts and struggle to adjust to your sleep schedule, leading to insomnia or excessive sleepiness, discuss this with your doctor.

7. Difficulty Concentrating or Memory Problems: If sleep problems affect your cognitive function, concentration, memory, or ability to perform daily tasks, seek help from a medical professional.

8. Partner Observations: Sometimes, it’s your bed partner who notices unusual sleep behaviors, like persistent snoring, long pauses in breathing, or abnormal movements, prompting you to seek evaluation from a sleep specialist.

Sleep challenges have many consequences on your physical and mental health, so best see a doctor if you experience any of these symptoms. A medical professional will check for any underlying sleep disorders and ensure to advise an appropriate treatment plan.


Understanding the different sleep stages can be crucial in helping you optimize your sleep hygiene. Core sleep encompasses uninterrupted periods of rest, including both deep sleep and REM sleep, which is vital for physical and mental restoration. By prioritizing strategies to promote deep sleep, such as maintaining a consistent sleep schedule, creating a relaxing bedtime routine, and managing stress, you can enhance your sleep quality and reap the benefits of a restful night's sleep.