The importance of sleep

In recent decades, people in our country have been sleeping shorter and shorter, with all the consequences that entails. Lack of sleep leads to reduced concentration, bad mood and intense fatigue. By sacrificing sleep, existing diseases can only recover moderately and new diseases lurk. Sleeping pills are among the most commonly prescribed medications. Together with the direct consequences of sleep deprivation such as accidents and absenteeism, sleep deprivation costs us billions of euros and, above all, our health.

Sleep is a basic necessity of life

It is still not entirely clear why we spend about a third of our lives sleeping. You can see sleep as a daily recurring state in which your body and mind relax because the muscles relax, heart rate and breathing slow down, consciousness is lowered and the outside world is ‘away’ for a few hours. During sleep, the brain refuels with new fuel in the form of glycogen. This sugar supply demonstrably runs out during waking periods. This is sometimes how sleep literally feels: The tank needs to be refilled in order to function on the new day. We cannot survive without sleep. Nature has arranged it in such a way that even if you try to stay awake, sooner or later you will fall asleep, and that makes sleep, just like eating, a basic necessity of life.

Lack of sleep

Anyone who sleeps too little or too little will notice this immediately in most cases. Lack of sleep affects the function of our brain, causing you to perform poorly or moderately during the day. Sleep deprivation causes a whole host of problems, including damage to memory, concentration and reaction speed. Your physical condition and emotions are also negatively affected by too little sleep. The annual costs of sleep deprivation in the Dutch working population are estimated at 3 to 4.5 billion euros per year. This concerns absenteeism due to lack of sleep, absenteeism due to lack of sleep causing other diseases, loss of productivity, and so on. Lack of sleep was also a crucial factor in 30% of traffic accidents. The importance of sleep is still greatly underestimated, but it is responsible for countless diseases, lack of recovery from diseases and affects all facets of life.

No time for sleep

The options for daily activities have increased so enormously in the last forty years that Dutch people have started sleeping about an hour less per day. In order to have as much time as possible for all the activities one wants to undertake, the duration of sleep is cut back and therefore modern people sleep too little. Forty years ago, people slept between eight and nine hours a night, but today this has decreased to more than seven hours. Television, the Internet and many other activities require constant attention these days. In short: People no longer have time to sleep. There is always a feeling that you have not seen everything, not read everything, not gotten everything out of the Internet that is there.

Today’s people go to bed with the feeling that the day was far too short. People no longer relax but run from meeting to party, from Internet to newspaper, from fitness club to friends, from children to television and back again. The demands we place on ourselves are so high that it seems easy to sacrifice sleep. People pay attention to nutritional habits, the usefulness of exercise, the importance of social contacts and acquiring knowledge, but what sleeping is necessary for is preferred to be forgotten, until the moment when the alarm clock wakes you up in the morning and you think: “No, don’t let it be true. I have to get out.”

Dead tired when you get up

Almost half of the Dutch are exhausted when they get up. People prefer to turn over again to stay in bed for hours. The first hour after getting up, people keep themselves going with strong coffee. There is little appetite for breakfast because the body is not yet ‘awake’ at all. People skip breakfast, or take a ready-to-drink breakfast drink, run to the office and have ‘something to eat’ along the way. Grumpiness in the early morning is no longer reserved for the few but has become completely normal. Many fall asleep during social occasions such as parties or cinema visits. There is often hardly any optimal functioning. Losing sleep occurs in all age groups, all occupations, and in both men and women.

Five sleep cycles

You can roughly divide the night into five sleep cycles with the same structure and a duration of 90 to 120 minutes each.
Each sleep cycle consists of five phases and these are distinguished by the level of brain activity and the sleeper’s eye movements. Only in the last phase of each sleep cycle does REM (Rapid Eye Movement) occur, where the eyes make rapid movements. The remaining phases are called Non Rapid Eye Movement phases.

The sleep phases at a glance

The sleep cycles are broken down below into the aforementioned five phases:

Phase 1

This is the transition between waking and sleeping, eye movements slow down and you have difficulty keeping your eyes open. This short phase lasts a few minutes. When brain activity has decreased sufficiently, you fall asleep.

Phase 2

This is a phase of light sleep that lasts about 45 minutes. Noises can no longer wake you up, but if you are woken up you will have the feeling that you have not slept at all.

Phase 3

This is the transition to deeper sleep. Breathing becomes completely regular, the heart rate decreases, and the muscles become completely relaxed. The duration of this phase is three to eight minutes.

Phase 4

The sleep is now very deep and if you were to be woken up now you would be disoriented and you would need time to realize where you are. This phase is the most important because physical recovery occurs. The duration of this phase is approximately fifteen to twenty minutes.

Phase 5

This phase is also called REM sleep and this is the part in which you dream. The brain processes all kinds of information and is highly activated, manifesting itself in sometimes bizarre dreams. Muscles of the arms and legs are virtually paralyzed in this phase, breathing and heart rate are irregular and blood pressure rises. This is not a restful phase but one that takes a lot of energy. The duration is about twenty minutes, after which you unconsciously wake up briefly and a new sleep cycle starts, from light sleep to deep sleep to REM sleep. And that five times a night, provided you take and get enough time to sleep.

The first three sleep cycles are the most important because the deep sleep, necessary for the recovery of body tissues, mainly occurs during these phases.

How much sleep is needed?

The minimum amount of sleep required to function properly during the day varies from person to person and depends on factors such as season, sleep history, age and daily activities. It is not a law that everyone needs 8 hours of sleep per night because the number of hours of sleep says nothing about the quality of sleep. If you have slept for eight hours and the alarm clock rings when you are dreaming or in the deepest sleep, you will still feel miserable when you get up. It is therefore important to assess your sleep needs based on how you feel during the day. Although after four hours of sleep you have completed your core sleep, i.e. the most important first three sleep cycles, you usually feel far from good when you get up. This partly has to do with the way of life, the urge to perform that prevails in contemporary society. Efforts are rewarded, relaxation is not. This way of life ensures high brain activity, meaning your brain is still running at full speed when you should be sleeping and even during the night itself.

Sleep and age

Babies sleep an average of 16 to 18 hours. This gradually decreases in youth, with a slight increase in sleep needs during puberty, ultimately decreasing until the age of about twenty years, when you usually get around eight hours of sleep per night. Children sleep more deeply than adults, especially early in the night. However, the older you get, the shallower your sleep because from the age of forty the deep sleep phase slowly becomes shorter. In the elderly, the deep sleep phase and REM sleep have often completely disappeared and that explains why they can lie awake often and for long periods of time at night.

To dream

A lot of attention is sometimes paid to dreams during sleep. Since prehistoric times, the view has prevailed that dreams contain messages of supernatural origin that are transmitted in a cryptic manner and must be interpreted accordingly. The idea that dreams reveal our hidden emotions has a lot of support. Some scientists consider dreams to be a meaningless phenomenon in the process of sleep, although the most common theory is that due to the high brain activity during the dream phases, dreaming helps clear, sort, store and erase memories and it may be precisely this phase of sleep. sleep is what makes the difference between remembering and forgetting things.
Dreams are visual. They consist of many images, which are, as it were, strung together. They are memories and fantasy images in bizarre combinations, a remarkable film. The eyes see nothing, because they are closed, but the parts of the brain that deal with seeing during the day remain active. The visual information we receive comes entirely from the brain but is processed as if it were real. Actually, dreams are visual hallucinations . You see things that aren’t there.


Nightmares are extremely fearful dreams with strong, negative emotions from which the dreamer in most cases wakes up abruptly. The nightmares can vary from a chase, getting lost, suffering pain, falling, drowning, seeing others die, repeating an unpleasant event or anything that can frighten a person. When the person wakes up there is first confusion and then relief realizing it was just a dream. Nightmares are tiring and can have consequences such as not daring to sleep and the development of insomnia. Nightmares are very common, almost everyone knows the phenomenon. It is estimated that half a million Dutch people have several nightmares per week. Children are very sensitive to nightmares, for example they dream about monsters under their bed or in the closet. This is normal and will go away on its own as the child gets older.

Nightmares come in roughly two types. There are nightmares that arise after a traumatic experience in which a repetition of the unpleasant experience takes place. These nightmares are called post-traumatic nightmares . They are intense nightmares that occur sooner or later in the majority of people who have had a traumatic experience. The second type of nightmares are nightmares without a specific background. They are bad dreams that have developed over the course of life and often revolve around a specific theme, such as falling and chasing. The environment keeps changing but the theme remains. In case of nightmares it is recommended to sleep in a cool room and use cooler bedding. It has been found that nightmares are promoted if the body warms up too much.

Factors that influence sleep

  • Noise disturbs sleep, especially deep sleep, even in people who are not woken up by it or are used to it.
  • Temperature. If the ambient temperature is too low or too high, sleep can be disturbed.
  • Bed. On a hard surface the body moves more than on a soft surface and increases the chance of waking up several times.
  • Power supply. A full or empty stomach prevents you from falling asleep.

Sleep disorders

Sleep disorders are debilitating. About 5% of adults sleep poorly at least twice a week, 15% sleep poorly less than twice a week and women have sleeping problems more often than men. Problems with sleep occur increasingly throughout your life. There are many causes, such as lifestyle, chronic physical conditions or psychological problems. As many as 1.9 million Dutch people (12%) take sleeping pills, often out of habit.

Sleep problem or normal?

  • People who sleep few hours but still feel good during the day can get by with less sleep and do not have to think that they have to sleep at least eight hours.
  • People who look at the clock and think they should sleep when they are not tired or sleepy at all will have problems falling asleep because they do not listen to their internal clock.
  • Older people sleep lightly and intermittently and that is not a sleep disorder but a normal side effect of growing older. Older people have a greater need for a siesta. The fixed sleeping hours become less ‘fixed’ and are often no more than six hours at a time.
  • Sometimes waking up briefly during the night, i.e. once or twice, does not mean that the sleep quality is poor, but is completely normal.

Real sleep problems

Sleep apnea

Sleep apnea is the temporary inability to breathe during sleep, causing your breathing to stop. This can occur several times a night, for a few tens of seconds at a time. This situation causes the person to return to a lighter sleep phase, disrupting the sleep process. Snoring is a manifestation of sleep apnea. During apnea, the trachea is temporarily partially or completely closed by resonating muscle mass and excess fat. Losing weight is an option, or using a CPAP, a mask that is placed on the mouth and nose that blows in a continuous flow of air and does not allow the trachea to close for a moment.


This is the well-known ‘insomnia’. There is difficulty falling asleep, one does not sleep through the night or is not rested after sleep. People often lie awake for hours, tossing and turning and worrying, even though they are definitely tired. During the day the sufferer is very tired, easily irritable and drowsy. Taking naps during the day increases the risk of insomnia at night and can thus perpetuate the vicious circle.


Narcolepsy is rare and manifests itself in fatigue, drowsiness and sleep attacks in which the patient suddenly has to close his eyes for half an hour. There may be an irresistible urge to sleep, attacks of muscle relaxation that last half a minute and can cause ‘fall’ accidents, sleep paralysis at night, hallucinations and poor night’s sleep. The complaints can be improved with medication.


Sleepwalking sometimes occurs, especially in children. A sleepwalker gets out of bed between sleep phases 3 and 4, can remain still or walk around. Putting on clothes is also possible. It is not dangerous because the sleepwalker avoids obstacles and can respond to others. However, it is not easy to wake someone who sleepwalks; it is better to guide the child to his bed. No memories are stored of this event, so the child will remember nothing about it the next day.

Facts about sleep

  • Counting sheep: According to researchers at Oxford University, counting sheep is not the best way to fall asleep. People who think of a flowing waterfall fall asleep twenty minutes earlier than sheep counters.
  • 40 Turns: We turn over in bed approximately every ten minutes, which is approximately forty times a night.
  • World record for staying awake: This record is held by Randy Gardner, a 17-year-old American student. In 1965 he stayed awake for no less than 11 days (264 hours) in a row. No idea how long he slept after that!
  • The average Dutch person goes to bed at 6 minutes before 12:30 and gets up again at 18 minutes past 7. This means that we spend an average of 7 hours and 54 minutes in bed per day (not the same as sleeping!) and that makes us the longest sleepers in the world.
  • Growth hormone is active at night and that means that children’s growth largely depends on the amount of sleep they get at night!
  • After-lunch dip: The sleepiness dip after lunch has everything to do with your biological clock. This not only synchronizes our day-night rhythm, but also plays a major role in maintaining alertness. This is highest around 9:00 AM and 9:00 PM, and lowest around 3:00 PM and 3:00 AM. In some people, the biological clock has shifted slightly and the dip occurs in the afternoon.
  • The British Melvin Switzer is the 1992 snoring champion. His snoring reached 92 decibels, which is louder than a jackhammer. His wife is deaf in one ear.
  • Light conditions drastically affect sleep and need for sleep. Since the invention of electric light, people have been sleeping shorter and shorter.


Whether or not to take the time to get enough sleep is a choice. If you have to sleep in for hours on the weekend, this means that you did not get enough sleep during the week, resulting in jet lag problems on Sunday evening/Monday morning. The infamous weekend migraine is also the result of a completely disrupted biological clock. Go to bed fifteen minutes earlier every night, as much earlier as you need to feel fit when you wake up in the morning. You’ll be surprised if you may need to sleep nine or ten hours to achieve this. But then you will also feel much better during the day than before. And that is worth a lot.

“The night is the hardest time to be alive and 4am knows all my secrets.” ~ Poppy Z. Brite