Quality of sleep vs Quantity of sleep

Written by Dr. Lozynska Liudmyla Yaroslavivna on Tue, 09 January 2024

Key Highlights

  • The quality of your sleep ensures that you get the essential physical, mental, and emotional benefits you need from your slumber.
  • Sleep is an important physiological need for an individual.
  • Most of the South Asian & African population is sleep deprived.
  • Both quantity and quality of sleep are important factors that needs
  • to be considered for good night's rest.

Do you feel sluggish and tired in the morning after waking up, or even on nights when you've had enough sleep? It's a frustrating experience, but there may be a simple explanation: you have poor sleep quality.

Lack of sleep can have a serious impact on day-to-day activities. It can affect your mood and is even linked to an increased risk of Alzheimer's disease.

It is easy to figure out that you are not getting any sleep. Figuring out why that sleep is not restful is even trickier, but it is certainly achievable. Read on to learn about quality and quantity of sleep, sleep cycle, the signs of lack of sleep, what could be causing your poor sleep quality, and how it can be improved?

What is sleep quality?

In simple terms, the quality of sleep measures how well you sleep. Measuring sleep quantity is simple, and is quick to determine if you're getting the recommended amount of sleep per night (usually defined as 7-9 hours for adults). "Measuring sleep quality is a little more of an art than a science." Generally, good sleep quality is defined by the following characteristics:

  • Falling asleep within 30 minutes of getting into bed.
  • Not waking up more than once in a night.
  • Getting the recommended amount of sleep according to your age group.
  • Falling asleep within 20 minutes even if your sleep is interrupted.
  • On waking up, you feel rested, restored, and energized.

What does quality sleep look like?

There are 5 stages of sleep and each stage serves a unique, important function in rejuvenating the body. One important thing is that you cannot reach the third stage of cycle without completing the second stage.

The last stage is 'Rapid eye movement (REM) sleep and occurs in cycles of about 90-120 minutes. Dreaming takes place in this stage, which may help process emotions and shape us mentally and emotionally. It is proven that that REM sleep aids in forming new memories, restoring and balancing chemistry of brain, and stimulating our central nervous system.

Those that suffer from REM such as sleep apnea repeatedly wake up throughout the night to catch a breath, which means that the progression of the sleep cycle is interrupted continuously. People suffering from sleep apnea or other sleep disorders usually do not reach at the last stage of sleep. Every time the patient tries to fall back asleep, he/she loses all the benefits of REM sleep. Constant interruption in sleep or poor sleep can lead to multiple chronic conditions, including memory problems and even long-term neurological damage.

Signs your sleep quality needs to improve

Healthy amount of sleep is not about being asleep for certain hours, but it is definitely an important factor to get good night's sleep; it is called sleep quantity. Just as important—and perhaps even more important—is sleep quality: this means regularly getting healthy, consistent sleep. It allows your body to go through all of the restorative processes that are necessary to maintain our overall health.

What is sleep quantity

Sleep quantity refers to 'how many hours of sleep' you get each night. According to the CDC, an average person's sleep needs are:

Age groupHours of sleep needed
Newborns (0-3 Months)14-17 hours per 24 hours
Infants (4-12 Months)12-16 hours (including naps) per 24 hours
Toddlers (1-2 Years)11-14 hours (including naps) per 24 hours
Preschoolers (3-5 Years)10-13 hours (including naps) per 24 hours
School-Age Children (6-12 Years)9-12 hours per 24 hours
Teenagers (13-18 Years)8-10 hours per 24 hours
Adults (18-60 Years)7-9 hours per night
Adults (61-64 Years)7-9 hours per night
Adults (65+ Years)7-8 hours per night

These guidelines are generalized, and there are people who need more or less sleep than the amount recommended for their age group.

What is sleep quality

Sleep quality refers to how well you sleep. Sleep quantity is one aspect of sleep quality, but it is not the entire picture. Other standards for high-quality sleep include:

  • Sleep Onset Latency: Sleep onset latency means how quickly and easily you can fall asleep. Most people are able to fall asleep within 20 minutes of going to bed.
  • Sleep Continuity: This is your ability to stay asleep once you fall asleep. High-quality sleep is continuous. Disrupted sleep at night is associated with less refreshing sleep overall.
  • Sleep Efficiency: Sleep efficiency means how much time you spend sleeping versus how much time you spend trying to sleep. Some researchers consider spending at least 85% of your total time in bed trying to sleep as a minimum benchmark for sleep quality.
  • Sleep Timing: Timing refers to when you sleep in a given 24-hour period. Our circadian rhythm dictates our internal clock and makes us feel alert at certain times (usually daytime) and sleepy at other times (usually nighttime). High-quality sleep is in line with the body's circadian rhythms. This means sleeping and waking at the same times every day.
  • Alertness During Waking Hours: Another indicator of quality sleep is your body's ability to stay awake throughout the day, which includes being wakeful, as well as being able to function with full cognitive as well as physical capacity.
  • Sleep Satisfaction: It can be measured by how well you have rested.

Sleep Cycle

During sleep, the body cycles through two types of sleep, 'non-rapid eye movement (NREM) sleep' and 'rapid-eye movement (REM) sleep', which is further broken down into four sleep stages.

Each stage of sleep is associated with characteristic changes in the body that are important to staying healthy and waking up feeling refreshed:

Sleep StageDescriptionLength
Stage 1This initial stage occurs as a person begins to fall asleep. Sleep is very light during this period as the body begins to relax.1 to 7 minutes
Stage 2Before the body enters deep sleep, this stage of light sleep is marked by a drop in body temperature and a continued slowing of breathing and heart rate.10 to 25 minutes
Stage 3The deepest stage of sleep, this stage is when bodily muscles are fully relaxed. and heartbeat and breathing rates are at their slowest of the night.20 to 40 minutes
Stage 4Stage 4 sleep is when a person enters REM sleep, in which their breathing and heart rate become more rapid as their eyes begin to rapidly move left and right.10 to 60 minutes

What gets in the way of high-quality sleep

There are many things that can cause disruption of a person's sleep quantity and sleep quality. Sometimes, the problem can be an underlying medical issue: this may be a sleep disorder such as insomnia or sleep apnea, or a psychiatric condition such as depression, anxiety, or bipolar disorder.

Apart from these conditions mentioned above, secondary conditions which interrupt sleep are kidney disease which can cause frequent urination, respiratory conditions which may cause difficulty in breathing.

Giving birth is the most rewarding experience in a women's life. But nursing an infant or taking care of young children might negatively affect the well-being of the women.

Also, the biological clock of those working night shifts and dealing with stress gets affected and this in turn impacts the body's circadian rhythm. It becomes very difficult for such people to adjust with the day and night shift.

Additionally, technology is one of the leading factors that disrupts sleep. Recent studies have suggested that sleep quality and quantity may also be reduced by light emitted from screens. Working late night and being plugged into the 24-hour digital world through various devices does not help at all.

Prevalence of insufficient sleep

  • A study published in the Asia Pacific Journal investigated sleep deprivation and its associated factors among undergraduate students in Malaysia. It was found that 58.1% of respondents were sleep deprived.
  • Prevalence of poor sleep and its associated factors among working adults in Malaysia was studied, and more than half of the participants reported sleep insufficiency. Age, smoking, and high levels of psychological distress were significantly associated with insufficient sleep.
  • In the 21st century, African descent populations in both the continent of Africa as well as throughout the world are experiencing a high rate of both sleep disturbances and cardio metabolic diseases. The most common sleep disturbances are reduced sleep duration, insomnia, disordered circadian rhythm, and sleep disorders like obstructive sleep apnea.
  • The Healthiest Workplace Survey* for 2019 showed that 46% of Sri Lankan respondents were getting 6 hours or less sleep each night, even though the optimal sleep time for health and productivity is considered to be a minimum of 7 hours.

What are the effects of poor sleep quality

Poor sleep has chronic health consequences, both in the short term and in the long term. It may increase your risk of developing concerns such as:

  • Cognitive, memory, and performance deficits
  • Stress and tiredness
  • Depression and anxiety
  • Cardiovascular diseases like hypertension, high cholesterol, heart disease, and stroke
  • Obesity
  • Lower immune function
  • Diabetes

How can you Improve Sleep Quantity and Quality?

Though constant sleep deprivation is troublesome, the great news is that there are many ways to improve both the quality and quantity of your sleep. Steps you can take to get better, healthier sleep include:

  • Addressing Underlying Issues: If you believe that you may have a medical issue that is impacting your sleep, you should discuss it with your doctor as soon as possible. Many of the most common medically induced sleep issues are treatable.
  • Make Lifestyle Changes: While certain parts of your life may be harder to change than others, there are a few steps that you can take that are likely within your power and may drastically improve your sleep. Getting regular exercise has been shown to improve sleep, as has cutting out cigarettes, alcohol, and caffeine in the hours before bed.
  • Invest in Your Sleep Environment: Most people underestimate the importance of their sleep environment, though everyone has their own preferences. People Commented [RS3]: Can you convert this into an inside graphic? generally tend to get the best sleep in dark, quiet, comfortable environments. Make sure your mattress and bedding are comfortable and consider investing in new ones if they aren't. If you find yourself interrupted by noise or light from outside, consider ear plugs or blackout shades.
  • Go Screen-Free: Though it may seem daunting to disconnect, studies have shown that bedtime phone use is associated with poor sleep. Using phones and other devices in bed also makes it more likely that you may lose track of time and can delay your actual bedtime significantly.
  • Practice Sleep Hygiene: Sleep hygiene means incorporating healthy habits into your life that promote healthy sleep. In addition to points mentioned here, practices like having a night time routine, maintaining the same bedtime whenever possible and winding down an hour before bed time, with a relaxing activity like reading, taking a bath, or meditating are very important.


So here is the ultimate question "Why quality of sleep is as important as quantity of sleep?" The answer is "focus on both sleep quality and quantity." Just like lack of sleep could make it difficult to function, poor quality of sleep could also leave you tired and fatigued throughout the next day and even affect your cognitive functions & frame of mind. You might not reach the REM sleep stage.

Appropriate amount of sleep & sleep quality could improve your mood better than sleep quantity alone, since uninterrupted sleep lets you obtain the optimal amount of restful and restorative sleep. We must focus on both quantity and quality for a good night's sleep, as sleep quantity and quality are inexplicably linked. To sleep as good as possible, you need to optimize both the amount of time you sleep and the things that impact the quality of your sleep.


Dr. Lozynska Liudmyla Yaroslavivna

She graduated from Lviv National Medical University. She has a specialization in psychiatry and psychotherapy. She have published scientific articles: “Anemia of Pregnant Women”; “Urinary Tract Infections”.

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  1. Mikailu Jandi Njayo

    Thu, 23 November 2023, 3 months ago


    • Good Health By Yourself Team

      Fri, 24 November 2023, 3 months ago

      Thank you!

    • Mikailu Jandi Njayo

      Thu, 23 November 2023, 3 months ago

      Very educative and informative knowledge.

      • Lawal Mustapha Musa

        Thu, 23 November 2023, 3 months ago

        Very educative


        Leave a Comment

        1. Sleepfoundation: How To Determine Poor Sleep Quality
        2. Pharmeasy: Quality Of Sleep Vs. The Quantity – Which Is More Important?
        3. Sleep Quality vs. Sleep Quantity - The Sleep Doctor
        4. Sleep Quality vs. Sleep Quantity - Sleep Better Georgia Blog (
        5. Asia Pacific Journal of Public Health. 2021;33(5):530-538. doi:10.1177/10105395211019930
        6. Chan, Caryn Mei Hsien et al. "Prevalence of Insufficient Sleep and Its Associated Factors Among Working Adults in Malaysia." Nature and science of sleep vol. 13 1109-1116. 13 Jul. 2021, doi:10.2147/NSS.S295537
        7. Frontiers | A Review of the Literature Regarding Sleep and Cardiometabolic Disease in African Descent Populations (
        8. 46% of working Sri Lankan's are sleep deprived - but why should employers care? (
        9. Stages of Sleep - The Sleep Doctor
        10. J Psychosom Res. 1997 Jun;42(6):583-96. doi: 10.1016/s0022-3999(97)00004-4. PMID: 9226606

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        Current Version

        Jan, 09 2024

        Written By

        Dr. Lozynska Liudmyla Yaroslavivna

        Dec, 02 2023

        Written By

        Dr. Lozynska Liudmyla Yaroslavivna