Every person spends one third of his life sleeping.  The sleep which we go through every day and which is a real miracle, contrary to what we know, is not a resting period at which all the body systems become passive. In fact, the body enters an active recuperating period. Now let’s see the recuperating period of the human body. 

Sleep is among the essential needs of the human life. Our body needs sleep as much as it needs oxygen and nutrition. Since one third of our life is spent during sleep, resting sleep has vital importance to carry on a balanced life. Sleep, is not a passive resting status. The activities, tensions and memorized information that keep the mind busy all day long are cleaned out during sleeping, like cleaning out a computer memory. During sleep, hormone level is balanced, digestive system works, immune system steps in, the skin is restructured. Cell division continues during sleep intensively.

What is regenerating during sleep?
Keeping our skin smooth is provided by getting rid of 10 gram dead skin cells every day. To do this, the division happens on the upper layer of our skin every night. This reaction accelerates as the growth hormone increases during sleep. The silence of the night is the ideal ambiance for this process because neither the sun, nor the wind can disturb the cell division. During these regenerating hours, the skin, oxygen being in the first place, needs a series of nutrition. At every breath, skin stocks the oxygen it needs. For this reason, ventilation of the rooms at nights before sleeping is suggested by experts. During sleep, especially during the hours we dream, the body temperature rises by 2 degrees and this causes the production of body fluids. This is why, when we wake up in the mornings, our hair might be damp and deformed. Since the sebaceous (oil) glands are regenerating at nights, oil secretion is generally low during sleep. In consequence, it is observed that  the ones with dry skin generally  wake up  with quite dried skin. The sleep experts state that the level of growth hormones in our blood increase substantially and suddenly as we fall asleep. Therefore, after every sufficient sleep, our body wakes up recuperated. 

For the last 50 years many  neurological, endocrinological and physiological researches about sleep have been carried on. Following that, currently we know lots of things about how we sleep, what changes happen when we sleep or cannot sleep.

When we fall asleep, our conscious level changes and we come and go between two types of sleep:
-non-REM sleep
-REM (rapid eye movement) or  paradoxical sleep

Non-REM Sleep
Non-REM sleep is generally divided into four stages based on the electroencephalographic changes which happens during the course of the sleep.

  • Stage 1 - Wakefulness changes entirely.
  • Stage 2 - Somnolence (or sleepiness). This is the situation when someone is about to fall asleep. If the person is woke up at this stage, s/he will say that s/he is awake even though s/he is not totally aware of what’s going on around her.
  • Stage 3 - During this stage, the conscious shows the EEG patterns that will be sufficient for the person that s/he can remember that s/he was sleeping when s/he is woke up.
  • Stage 4 and 5 - Slow wave sleep

REM Sleep
Rapid eye movement (REM) sleep is the stage when we dream. This stage happens between the other stages. It is related with many different features. It is also known as paradoxical sleep, since, in the beginning, even though the rapid eye movements accompanied by uneasiness made the researchers think that this stage of sleep is light, muscle paralysis allowed them to state that it is a heavy sleep paradoxically as well.

The Night Pattern of the Sleep
When we fall asleep, we pass through the four stages of the non REM sleep in a rapid fashion and the most of the first ninety minutes is mostly spent at stage IV sleep, followed by a ten minutes REM sleep. This pattern repeats itself four or five times during the night, but every time REM sleep gets longer. Before we wake up, we spend nearly 1 hour at REM sleep. The sleep percentage spent at REM sleep changes decreasingly after birth: 50% at birth, 33% at 3, %27 at eleven and %25 at adolescence.  

Sleep and Wakefulness
The daily rhythms of the body are well known. Sleep is one of the many body functions tightly connected to these natural rhythms. The importance of these rhythms during sleep emerges after a long air travel. We perceive that  our body clock is not set according to external stimuli which are related to sleep and wakefulness. The people with sleep disorders are the ones whose sleep and wakefulness rhythms  are generally off the track. These are usually the people work  at night shifts, parents with small babies, or who are used to wake up late, and cannot fall asleep at nights. The sleep pattern of most the Mediterranean countries, such as sleeping in the afternoons during work breaks, especially in hot weathers, is more close to our natural sleep pattern than the ones in North America or North Europe. 

Hormones and Wakefullness
Adrenaline and corticosteoid levels are higher when we are awake – actually, adrenaline levels are very low when are asleep. On the other hand, growth hormone and other regenerating hormone levels are higher.

When, How much Should We Sleep?
Daily sleep time changes according to the person anda ge. Generally sleeping time decreases as the time passes. However, 6 to 8 hours daily on average is usually enough for an adult. People who often cannot sleep deeply, are more weak against the diseases. In such circumstances, the rhythm of the body gets out of control. This imbalance reflects on the skin: skin dries, flakes off and since the cell division cannot take place regularly, skin gets thinner. As the dry skin gets drier, rough skin breaks down more.

The experts state that the most ideal time for sleep is night hours. They do not suggest day time sleep to reinforce any kind of sleep disorders, but emphasize night sleep. However, since the cell regenerating and hormonal reactions happen only at nights, contrary to what we know, siesta has no contribution, because the melatonin hormone is produced after dark by our brain. This hormone starts the regenerating of the skin.

Physiological Factors
It is not common for everbody to sleep 8 hours, It changes person to person. For some people longer hours are needed, whereas for others 3 or 4 hours can be enough.

The history is full of successful leaders’ stories who only sleep a few hours every night - Napoleon and Churchill are two of them. On the contrary Einstein was a long sleeper who sometimes slept 16 hours of the day. 

The amount of the sleep changes according to the age. The new borns may sleep up to 20 hours. Around the age of 2 the need for the sleep decreases, but however, kids still need longer hours to sleep than the adults do. At the future part of the childhood the average need for sleep is only a little bit higher than an adult’s average need. During adolescence the sleep patterns become variable and some teenagers need more sleep when they were 11. Around the ages 16 – 17 most of the people acquire the sleep pattern that will last around 45.

Elder people tend to sleep lighter and they need less sleep when they did at younger ages.

At the age of 70 the average sleeping time is 6 hours (since this average is a value most of the people may sleep less). Most of the people who complain about insomnia actually sleep normally according to their ages, but they compare it with their sleep styles at younger ages.

Environmental Factors
More importantly then these individual differentiation, the average sleeping time of a society effects from external factors. For instance, before the general consumption of the electiricity, people based their sleeping patterns according to the patterns of the day light. This situation was more obvious at higher places where the amount of the day light was changing substantially according to the seasons. We are naturally prone to sleep at the same time with the people around us. We shouldn’t be surprized that darkness is one of the main enactors of the sleep at all societies. If this natural rhythm diverses like at night shifters, the problems with sleep emerge often. 

The first clause of a healthy sleep is to know our sleeping hours and the duration and going to bed and waking up accordingly. Even though it not possible to comply with our sleeping at exact hours every day, it’s better to move according to our sleeping hours for the healthy sleep.

When we use our body less, but our mind more, it may end up with tension which may make sleep difficult. Physical activities such as walking, jogging, playing tennis or swimming at spesific days of a week, make us relax, thus, form a basis for a good sleep.

Physical activities, especially such as heavy gymnastics which stimulate autonomous nerve system,  are not suggested right before sleep or at late hours since they ruin the quality of the sleep. 

Since eating excessively at evening hours may discomfort the stomach, especially the ones with respiratory disorders and snoring problems should pay attention on this point.

Excessive liquid intake will not only disturb the stomach, but also will cause the need to go the toilets, it’s better to pay attention on liquid intake.

Even though alcohol makes it easy to fall asleep, since,  especially during the second half of the sleep it may cause awakenings, it is considered as a sleep disturbing factor and it shouldn’t be consumed at large amounts at nights.

The drinks which are known as stimulant may also break the sleep structure and make it harder to fall asleep when consumed in the evenings. Thus, too much tea, coffee and frizzy drinks shouldn’t be prefered in the evenings

The dinner should be eaten a few hours before sleeping. A warm glass of milk or linden tea with a few biscuits will make it easy for you to fall asleep.

Keep your room cool all the time. The room should be cool since your body tries to lose temperature when it is about to fall asleep.

Sleep at dark because the substane that makes the people sleep can be secreted at nights.

Do not judge your day or plan about your next next day when you get into bed.

However, some experts think that reading a restful book which doesn’t tire our mind can make it easy to fall asleep.