Why is Sleep so Important to Your Physical and Mental Health?

Sleep is one of the essential parts of life and a healthy body, in addition to nutrition and physical activity. Unfortunately, a relatively large portion of the population fails to attend to their sleep as much as they do to the other parts of maintaining a healthy life.

The latest sleep study in the UK revealed that around 35% of the national population experienced sleep-related problem in the past five years. Up to 20% of adults in the UK reported experiencing such problems within the last decade.

The study also revealed that more than half of respondents felt a lack of energy after a poor night’s sleep, as well as disturbances in their mood and poor performance at the office.

We all know sleep is key to our physical and mental wellbeing - a good night sleep can help fend off everything from stress to heart disease. Yet, many people still fail to ensure they get enough sleep. 

A large percentage of the population also fails to understand why exactly sleep is essential – which is what we will uncover below.

How Sleep Works and Sleep Stages

To understand why sleep is important, looking at what happens in the body during sleep first needs to be discussed. Sleep occurs in cycles – we go through many cycles in a single night, as each cycle tends to last for around one and a half hours (about 90 minutes).

During each sleep cycle, our body goes through alternating stages of both non-rapid eye movement sleep, also known as NREM sleep and rapid eye movement sleep, or REM sleep.

NREM sleep consists of four different stages, and we spent 75% of each night in this mode. The other 25% of sleep is spent in the REM sleep phase.

The four stages of NREM sleep include:

  • Stage 1 or N1This is also called light sleep and is the phase that occurs when a person just starts to fall asleep. They are not fully asleep, but also not awake.
  • Stage 2 or N2 – This happens once a person falls asleep. Their brain disconnects from their surroundings, they start to become unaware of all external factors, and their body temperature reduces slightly.
  • Stage 3 + 4, or N3 – New data surrounding the various sleep stages of NREM sleep have suggested that stage three and four be combined into one new category, known as N3. This is one of the most critical phases of sleep. The body restores on both a physical and mental level. At this stage, you start to breath slower, the body's muscles relax, and the blood pressure reduces a little. At the same time, the blood circulatory system works hard to deliver more blood to muscle tissue.Several hormones are also released during the N3 sleep phase, including growth hormone. During this stage of NREM sleep, the body also repairs damaged cells and tissues.

After the first 90-minute cycle of sleep, the body goes into a short period of REM sleep. During this phase, both physical and mental energy is restored. The brain becomes active during the stage.

 Muscles in the body are switched off, and we transit into a relaxed state. This is when dreaming occurs. After a short period of REM, a new cycle commences. After every 90-minute cycle, the body goes into REM – each time the body enters REM sleep, it lasts a little longer than the previous phase.

Sleep Deficiency Causes Poor Mental and Physical Wellbeing

An average adult needs to ensure they sleep at least seven hours per night to ensure their body can go through the appropriate processes necessary to maintain overall physical and mental health.

When a person fails to sleep enough, it means they are exposing their body to a large number of potential adverse effects – some of which can be detrimental to their health and even lead to a lower quality-of-life.

The entire human body – both physically and mentally – are affected by sleep deprivation.

It's essential to understand precisely how a person can be affected by poor sleep, as this would allow them to understand better why sleep should be a priority in their life.

Mental Problems Linked to Poor Sleep

Problems Linked to Poor Sleep

Mental health is a subject that has a considerable impact on overall wellbeing, as well as quality-of-life.

Unfortunately, many fail to take their mental health seriously. This often leads to impairments and mental health issues that cause a significant adverse impact on the person’s life.

Depression: Poor sleep, in particular, can take a hefty toll on mental health. Depression is one of the most important topics to be discussed when it comes to connecting poor sleep to poor mental health.

Even though a bi-directional connection exists here, a person who does not attend to their sleeping habits can develop new depression or experience worse symptoms of existing depression.

General cognitive impairment: this may include memory problems and difficulty focusing on tasks, also become quite problematic.

Other psychological effects can be experienced with sleep deprivation, especially when this problem becomes a chronic health concern.

In addition to depression, poor sleep is also linked to somatoform disorders, as well as anxiety. People who do not make sure they sleep enough are also likely to experience mood alterations.

Physical Health Issues Associated with Poor Sleep

The physical problems that come with poor sleep should also be understood as these can not only lead to the manifestation of unpleasant symptoms but can also lead to potentially life-threatening situations.

A lack of sleep has a strong link toward obesity. Studies have shown that people who sleep less than seven hours per night are far more likely to gain excessive amounts of weight and become obese when compared to those who do obtain enough sleep.

In turn, obesity can also expose a person to many health ailments and the possibility of developing a specific chronic disease that has been linked to premature death.

Individuals who are deprived of quality sleep are known to experience some of the following physical complications:

  • A higher cortisol level in their bloodstream in the evening than what is considered normal or healthy.
  • A higher level of ghrelin, which is often referred to as the body’s hunger hormone.
  • A reduction in cellular sensitivity to insulin, which can lead to insulin resistance.
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    Leptin levels are also likely to become reduced in sleep-deprived individuals.

Sleep deprivation has also been linked to hypertension. In previous studies, it was suggested that the connection between poor sleep and hypertension is related to the fact that obesity is common among people who fail to attend to their sleeping habits.

A review paper by the Pennsylvania State University College of Medicine, however, found that the risk for hypertension exists even without excessive weight gain.

Effects of high blood pressure include:

  • Heart failure 
  • Kidney failure
  • Coronary heart disease
  • Raised risk of a stroke

Benefits of a Good Night’s Sleep

Did you know that sleeping can improve your alertness, attention span, concentration and problem solving capabilities?

Now that we have looked at what can happen to a person’s physical and mental health when they do not sleep enough. Next, we want to turn things over to the positive side – by looking at the many benefits that come with a good night’s sleep.

We already explained what happens during sleep – the body is recharged and gets ready for the next day. What this essentially means is that healthy sleep means healthy levels of energy the upcoming day.

Since the mind also gets a chance to rest, concentration and alertness the following day will also be significantly enhanced – important factors that play a crucial role in being productive at work and performing many day-to-day activities.

Other particular benefits that people should also be aware of that comes with sleeping at least seven hours each night:

  • Sleep improve the immune system: when a person ensures they gain enough sleep, it means their immune system will benefit in the process. At least seven hours of sleep daily can significantly improve the immune system's ability to fight off illnesses, viruses, and bacteria; thus preventing infection. This can also help to reduce inflammation in the body
  • Help to reduce levels of cortisol: This is the stress hormone in the body. Reduced levels of this hormone leads to lower stress levels and also helps to reduce the impact of stress on the body.
  • Proper blood circulation in the body: for athletes and anyone who is physically active, and this is the perfect time for torn muscle fibers to be healed and restored. This can significantly reduce muscle pain and stiffness after strenuous workouts.
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    Improved moods: Enough sleep also makes a person less likely to feel moody the next day. Poor mood can lead to a number of possible adverse effects, including problems socializing. With proper sleep, however, a person experiences an uplifted mood and finds that interacting with others become much easier. People who gain enough sleep also tend to be happier as compared to only getting a few hours of sleep.
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    Energetic and alert all day: Adequate amounts of sleep ensure a person is alert during the day and makes them less likely to experience daytime sleepiness. This, in turn, puts them at a significantly lower risk of being involved in an accident – be it a car accident or while operating heavy machinery in a factory.
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    Helps in weight loss: Sleep deprivation causes people to overeat and feel hungry all the time, but proper sleep, on the other hand, helps to balance the particular hormones in the body that controls hunger and satiety. This means gaining enough sleep will contribute to weight loss, if implemented as part of a weight loss program, instead of increasing the risk of becoming obese.

Bedtime Habits Worth Adopting for a Better Night's Sleep

woman having quality sleep

Sleep is important – that is clear by now. When stress and other problems get a person down and make them lie awake in bed, it is essential that they learn how to adopt healthier sleeping habits. There are many benefits to healthy sleep – and simple methods can greatly help.

Ways to improve your sleep duration and quality:

  • Avoid alcohol and caffeinated drinks: Alcohol, coffee, and smoking should ideally be avoided close to the bed. These can all keep a person awake and make sleeping more difficult.
  • Turn off bedroom lights: Any lights in the bedroom should be turned off – this includes LED lights. An alarm clock should be pointed away from the bed. The darker the room, the easier it will be for the person to sleep.
  • Light exercises: Even though exercise is known to boost energy, participating in light exercises like yoga, cardio (aerobic) exercises regularly can help you improve sleep – as long as the exercise protocols are not performed too close to bedtime.
  • Pick the right gear: Sleeping on the right mattress and pillows promotes better sleep. Additionally, regularly cleaning sheets can also be helpful. A great cooling pillow can be helpful in providing for proper spine alignment during summer and help to make sleep more comfortable.
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    Avoid distractions before bedtime: The 2016 UK Sleep Survey found that millions of people spend as much as an hour watching TV, reading, socializing on Facebook and browsing around on the internet before they decide that it is time to sleep. These are all distractions – avoiding any distractions and rather participating in relaxing activities an hour before bed can be very helpful.
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    Set alarm: While most people are used to set the alarm to help them get up in the morning, considering an alarm to remind them to get ready for bed at night can also be helpful.


While it is generally known that sleep is important, many do not understand why and are not sure how they can make sleep more of a priority in their lives. A busy, stressful life often leaves little time for the right sleep duration and, of course, quality. This, however, does not mean making sleep an important part of a healthy lifestyle is impossible. Simple tips can be used to adopt better sleeping habits and enjoy the vast number of benefits that seven to nine hours of sleep per night has to offer.

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