What Is Sleep Anyway? | All You Need To Know About Sleep Review


Probably nothing is taken for granted by us humans as the natural need for sleep. But have you ever thought about what sleep actually is or what it actually does?

After all, there is absolutely no wasted time, as some claim. Even though we spend a good third of our lives asleep.

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Polyphasic sleep

Patrick Klein
in magazine

Healthy sleep is essential for each of us to stay fit during the day. It also gives the body the opportunity to recover from exertion, regenerate and recharge its batteries. For this we go through different sleep phases […]

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Problems falling asleep

Lea Vogler
in magazine

Hardly anyone likes it when you turn from one side to the other at night and just can’t get any rest. The reasons for this can be very varied, as the causes of insomnia are also different. Even if you […]

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Too much sleep

Lea Vogler
in magazine

To suffer from a sleep disorder without knowing it sounds absurd at first. Nevertheless, the estimated number of unreported cases of sleep disorders is very high. So too much sleep can be a reaction of the body to show you that your sleep […]

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Sweating at night: Possible causes and prevention

Lea Vogler
in magazine

Who hasn’t? You wake up in bed after an already often restless night sweating. Your pillow is wet and your hair sticks unpleasantly to your skin. And again you have to change the bed and take a long shower. […]

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Healthy sleep

Lea Vogler
in magazine

Did you know that you can’t survive more than eleven days without enough sleep? But who wants that? But not every night’s sleep is actually the same as healthy sleep. To be able to start the next day with more energy […]

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Lea Vogler
in magazine

Are you one of those people who suffer from insomnia? The reasons for these disturbances of the natural sleep-wake rhythm can be of very different nature. As a rule, insomnia can also be combated well – if you know what you are looking for […]

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Sleep deprivation

Patrick Klein
in magazine

Not only new parents suffer from it, but also a lot of people who could actually spend the night undisturbed: lack of sleep. After the first few nights, most people experience bad mood, persistent tiredness during the day and lack of concentration […]

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Chronic fatigue

Lea Vogler
in magazine

Feeling constantly exhausted and having no strength for everyday life is an almost unimaginable burden for body and soul. Nevertheless, chronic fatigue, especially in combination with other diseases, is not uncommon. The body signals with the constant […]

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Fall asleep quickly: 8 useful tips for falling asleep quickly

Patrick Klein
in magazine

You lie in bed for 30 – 60 minutes with your eyes open and can’t fall asleep? Then you should get to the bottom of the cause,

In this article we want to clarify the most important questions about sleep. It should help you to get an overview of the whole topic and provide an exciting introduction. Among other things, we briefly deal with the different sleep phases, how much sleep a person actually needs and whether too little sleep can become a problem.

It is also exciting to find out what constitutes healthy sleep and how you recognize healthy sleep. We also want to give you tips on how you can improve your sleep so that you can get up the next day full of energy.

The most important facts in brief

  • Sleep is a state of rest in which your breathing rate, pulse and blood pressure drop. In addition, depending on the sleep phase, brain activity and muscle tension change.
  • Sleep is especially important for the regeneration of your body, both mentally and physically. Events are processed and cell regeneration is activated.
  • Permanently too little sleep has a negative effect on your health. The result can be problems with your cardiovascular system. Sleep researchers recommend about 7.5 hours of sleep per night.

What is sleep?

Sleep is the state in which your body is externally in a state of rest. But you should not compare this with a quiet afternoon on the sofa or in the garden. Because even if you enjoy a lot of rest there in some moments, you have not yet reached sleep as such.

The sleeping phase can be easily distinguished from the waking phase, because while you sleep:

  • your respiratory rate and blood pressure drop
  • your pulse slows down
  • changes, depending on your sleep phase, your brain activity and your muscle tension

Apart from the fact that you will certainly enjoy your sleep to the full every night, night sleep has a completely different meaning. During sleep your body can regenerate quite well. This means that you are not only recharging your batteries for the next day. It also means that cell renewal is activated.

Even in psychological terms, sleep has a very important meaning. Because what you learn and experience during the day is optimally processed during the night and the brain literally re-sorts it. Especially newly learned things can be better recalled the next day.

Backgrounds: What you should know about sleep

Before we begin to deal with healthy, relaxing sleep, we will first discuss some background information about sleep. For example, we clarify how much sleep a person needs, which sleep phases there are and what effects too little sleep can have.

How much sleep does a person need?

How much sleep each individual person needs cannot be squeezed into a mathematical formula. This is because sleep requirements vary from person to person. Individual needs, living conditions and also the respective age play an important role.

So if you hear or read about an optimal sleep duration of seven to eight hours in an adult, this does not have to be understood as an absolute must-have. Of course, it is just as well if you only sleep for six hours or even nine hours. It is important that you have a healthy sleep and feel fit and rested in the morning.

How long do adults sleep and how long do children sleep?

The need for sleep is just as different as the sleep behavior. Children for example have

In view of the different sleeping needs of children and adults, you should never think in too rigid boundaries. Because the respective life circumstances and genetic disposition always play a role. Therefore, you should see the following times as an orientation guide rather than as an absolute must.

    Babies up to 3 months usually sleep between 14 and 17 hours. However, 11 to 13 or 18 to 19 hours are still within the green range.
    Babies between 4 and 11 months usually sleep between 12 and 15 hours. But 10 to 11 or 16 to 18 hours are also not uncommon and not yet a problem.
    Infants between 1 and 2 years usually need 11 to 14 hours of sleep. But some also sleep between 9 and 10 or 15 and 16 hours.
    Children between 3 and 5 years usually sleep between 10 and 13 hours, whereby 8 to 9 hours are just as normal as 14 hours.
    School children between 6 and 13 years of age sleep optimally between 9 and 11 hours. But 7 to 8 or 12 hours are also possible.
    Teenagers between 14 and 17 years should sleep between 8 and 10 hours. But 7 to 8 or even 12 hours are also conceivable.
    Young adults between the ages of 18 and 25 usually need 7 to 9 hours of sleep. But 6 or between 10 and 11 hours are also considered normal.
    Adults between 26 and 64 years of age usually only need 7 to 9 hours of sleep, although only 6 or sometimes 10 hours is not unusual.
    Older adults over 65 years of age again have a somewhat reduced need for sleep. Between 7 and 8 hours are often normal here. But also only 5 to 6 hours are conceivable, and 9 hours are quite possible.

Even with children, the entire daily routine or life situation is decisive. For example, a school child will certainly need more sleep if he or she is still active in a sports club after school instead of just sitting in front of the television. Similarly, an emergency doctor on call for years will certainly manage with less sleep than an office worker, for example.

What happens if I don’t get enough sleep?

In principle, it will certainly not be a problem if you sleep a little too little from time to time. Maybe the party went longer than you thought or because of a cold you don’t calm down as fast as you are used to. But as soon as this state of insomnia or lying awake at night becomes more frequent, caution is advised. Because if you do not sleep enough in the long run, this has a lasting effect on your body.

Sufficient and healthy sleep is vital for you and your body. Only in a sufficiently long sleep phase can your body renew old and defective cells and activate certain processes in your organism.

Sleep researchers recommend that the average person gets about 7.5 hours of sleep per night. In fact, most people regularly sleep too little, only 7 hours.

Frequent or permanent lack of sleep has a very negative effect. So you will already notice on the first day after a shortened night that you:

  • are not as efficient as usual
  • you have major concentration problems
  • you are tired and exhausted

If these restrictions occur only occasionally or rarely, you can certainly live with them. At least if you have a generally good health condition. However, if you suffer frequently or even permanently from sleep disorders that ultimately cause you to sleep too little, this can quickly lead to secondary diseases and very negative effects.

Too much sleep deprivation results:

    For faster weight gain, as there is often a greater need for food due to lack of sleep.
    To the increased risk of developing Alzheimer’s disease or dementia. Because the brain cannot regenerate sufficiently due to the lack of sleep, massive memory problems occur, which can quickly develop into a serious disease.
    To an unhealthy imbalance of the blood sugar level. For example, if there is a permanent lack of sleep, there is a risk that insulin resistance will increase by up to 30 percent. The reason for this is also the lack of a regeneration phase, which can only take place during sleep.
    To an increased risk of cardiovascular diseases. For example, the negative effect on blood pressure is one of the reasons why heart failure can occur up to 60 percent more often if too little sleep is taken. Likewise, the probability of suffering a stroke or heart attack is twice as high.
    To an insufficient or even inhibited self-healing process in the body. Because defective or old cells cannot be regenerated sufficiently.
    To a premature aging process, because the skin cells are not sufficiently moisturized without sufficient sleep.
    To an undersupply of growth hormones. For example, fat deposits cannot be broken down and the metabolism of the bones is massively disturbed.
    To mental illnesses. Depression in particular is the consequence of lack of sleep, which occurs very frequently and draws every person affected into a real vicious circle. Depressive or other mental illnesses often cause massive sleep disturbances, which in turn result in sleep deprivation.

How do I determine my individual sleeping needs?

Every person has a different need for sleep. On the one hand this is due to the individual life situation, age, but also to the genes. It is also possible that you can manage with seven hours of sleep, while your friend or brother of the same age always needs around nine hours of sleep to be really fit.

If you want to find out how much sleep you actually need, you should answer these questions:

  • After what length of sleep do you feel optimally rested and fit?
  • Do you suffer from overweight or a previous illness that puts you in a risk group?
  • Do you sleep well at night?
  • Do you wake up several times during the night and find it difficult to fall asleep again?
  • Do you absolutely need enough caffeine in the morning to be able to start at all?
  • Do you often feel tired and drained during the day?
  • Are you tired quickly when you have to concentrate especially?

In order to be able to determine exactly how long you sleep, how often you wake up and whether you sleep restlessly, it can help if you get a sleep tracker. In addition, this small device can also help you with a self-test.

The best time to do this little self test is when you have a few days off. Because often it can also be because you did not know your own biorhythm, i.e. your sleep-wake rhythm, very well.

For example, if you often have problems sleeping through the night, one of the reasons may be that you simply go to bed too early. On the other hand, if you need a pot of coffee in the morning to be really fit, you may go to bed too late.

Can you catch up on your sleep?

It will probably also happen to you more often than you would like that you do not get enough sleep. Maybe simply because you had to work overtime, but in the evening you were surfing the Internet too long or a surprise visit didn’t come so early. But what do you do if you do not get enough sleep in these exceptional cases?

As long as your lack of sleep is not of a permanent nature or caused by illness and sleep disorders, you can catch up on sleep. As a study by the Stockholm Karolinksa Institute found out, it is quite possible that an otherwise healthy person can make up for the need for sleep. Possibly at the weekend, because during the week there was simply too little time in everyday life.

If you do not only pay attention to a healthy lifestyle, but also get as much exercise in the fresh air as possible, you will normally not have to worry about getting too little sleep.

The same study underlined however also again that permanent sleep deprivation makes ill and even the risk to die earlier increases massively. Thus permanently 5 hours sleep are simply too little, said the scientists. However they could manufacture also a connection between the decreased sleep duration under the week and the death risk in their study. If the lack of sleep is balanced on the weekend again, the death risk does not increase substantially.

By the way, not only is too little sleep harmful when it becomes a permanent affair. Too much sleep can also be unhealthy. Too much sleep can be a sign of a depressive or other mental illness. If it happens more than three times a week that you sleep too much, this can result in unwanted and uncontrolled weight gain, and you can get diabetes. In addition, the risk of a heart attack increases in this case as well.

What types of sleep are there?

It is also irrelevant for a healthy sleep, which kind of sleep each individual prefers. Of course, there are a lot of differences between the different types of sleep. The individual sleepers are divided into:

In addition, however, a distinction is always made according to sleep types. It depends on whether someone sweats quickly and heavily or is cold. These distinctions are particularly important when it comes to choosing the right mattress, mattress protection and bedding.

With the different sleep requirements of humans, the term “sleep pattern” is often used. Of these, the following three are particularly interesting for you:

  • Polyphasic or multiphase sleep: The need for sleep is divided into at least three bedtimes per day. You can best observe this with babies and toddlers.
  • Biphasic sleep: In this process, a person’s sleep requirements are divided into naptime rest and nighttime rest. So you sleep twice a day.
  • Monophasic sleep: Here you sleep only once a day, usually at night. You probably know this too, because you can’t always lie down for an hour at lunchtime when you’re tired.

By the way, biphasic and monophasic sleep are the sleep patterns that are typical for adult people. On the other hand, polyphasic sleep in adults is often artificially trained in order to minimise sleep times over a longer period of time, for example for cyclists.

Which sleep phases are there?

The sleep is divided into different sleep phases. In an adult person, there are a total of five phases of sleep, which together form a cycle. This cycle usually lasts around 90 minutes and is repeated three to five times each night.

In addition to the falling asleep phase, the light sleep phase, the deep sleep phase and the wake-up phase, this also includes the so-called REM sleep. This abbreviation stands for rapid eye movement. Translated, it means as much as: rapid eye movement. So it means that your eyes move quickly during the REM phase.

In general, this REM sleep phase is also called dream phase. This term is usually a little more common and is used more often. Of course it is also easier to explain. Because in this phase of your sleep cycle you dream more intensely.

By the way, during the first half of the night you are usually in the deep sleep phase, while in the second half of the night you experience the REM phase. This is why you can usually remember these dreams better, because REM sleep in the second half of the night prepares your body for awakening. For this reason, you can usually remember these dreams more easily then.

Sleeping: Information and tips for a good night’s sleep

Sleep is probably the best thing that can happen to us. Because it brings us and the rest we need to cope with our everyday life. It is also extremely important so that our entire organism can regenerate sufficiently overnight.

What is a healthy sleep?

A lot in your life depends on a healthy sleep. Starting with feeling fit and vital in the morning and ending with a well regenerated body in the morning. In addition, healthy sleep usually wakes you up by itself rather than by the alarm clock. In addition, you will quickly notice from your concentration and performance ability whether your sleep was healthy and restful or not.

Other characteristics by which you can recognize that you have a healthy sleep

  • your falling asleep phase lasts only a short time, which means that you are already well asleep after a maximum of 15 minutes
  • you can sleep through the night without staying up for a significant amount of time in between
  • you do not roll restlessly from one side to the other during the night or startle at the slightest noise
  • you do not feel tired or exhausted during the day
  • you can concentrate well and easily even with great effort

When doctors and experts talk about healthy sleep, they always include sleeping through the night. However, you should know that every person wakes up several times a night.

Usually you don’t notice this, because if the sleep phases are undisturbed, this happens rather unconsciously. Only if you regularly lie awake for a longer period of time after these short waking moments and make an effort to get back to sleep well, your sleep will not be one hundred percent okay.

What do I have to look out for in order to sleep well?

In order to experience healthy sleep, however, it is always important not only to know your own biorhythm. Because only the optimal sleeping environment, including the perfectly coordinated bed equipment, as well as sleep hygiene, a healthy lifestyle and the right sleep patterns, can turn a simple night’s rest into truly healthy sleep.

Sleep rituals can be helpful if you want to get a quick and healthy sleep. In this way you signal to your body before you fall asleep that it is now time to rest.

Pay particular attention with your bedding that the mattress and also the blanket and pillow are adapted to you and your needs. In addition, you should rigorously ban disturbing light and noise sources from your bedroom, as they can prevent you from falling asleep.

But the room temperature of your bedroom should never be much higher than 18°C, because it is simply too warm to sleep. In addition, it is always a good idea to air the bedroom briefly before going to bed to let enough oxygen into the room.


Sleep is therefore a very extensive topic. Besides physical recovery, good sleep is also particularly important for mental recovery. The different sleep phases have different meanings for the regeneration of your body. For example, in the REM sleep phase feelings and information are processed, while in the calm deep sleep phase the body relaxes and regenerates.

Too little sleep can be very harmful to the human body in the long run. Besides minor symptoms such as a slower reaction or lower concentration, too much sleep deficit can cause major problems for the cardiovascular system. To ensure that you get a good night’s sleep, we recommend that you darken your room completely, use the right mattress and keep your bedroom rather cool. Rituals can also improve sleep quality.

Further sources and literature

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