What is sleep?

Although sleep is taken for granted by many of us, the health relevance of sleep is often neglected. Sleep is understood as the state of external rest of the person, pulse, breathing and blood pressure are lowered, while the brain continues to work. Man spends about 30% of his time in sleep, sleep is absolutely necessary for man and beneficial to health. Those who sleep too little run some health risks.

Heart disease
Decreased performance
Diabetes
Mental illness
Overweight

These are just some of the consequences of sleep deprivation. Many people also fail to realize their potential because too little sleep makes them unfocused, more irritable and unable to perform to their full potential at work, school or training. Especially in the working world, this is often a vicious circle: we stay awake longer and work more, but at the same time our performance drops due to this extra strain and more working time is needed.

Some important functions of sleep for the human body

Good sleep is important

Good and restful sleep has a whole range of important functions for the body.

The body regenerates during the night hours and muscle growth occurs. Those who train or work in a physically demanding way especially need these regeneration phases, as this is when the muscles regenerate and grow. Too much training with too little regeneration can lead to premature exhaustion and injuries.
Harmful and hazardous substances are broken down during sleep.
During sleep, the experiences of the day are processed and the memory is reorganized. Newly learned things are deepened, connections between the learning contents are deepened and finally unimportant things are forgotten. If you have to learn a lot of new things, you should make sure you get enough sleep. Unfortunately, sleep comes too short, especially during exam phases.
Sufficient sleep is also important for the immune system. Medical studies have shown that little sleep makes it easy for cold viruses, for example. On the other hand, people who sleep seven hours or more have significantly better defenses.

In a nutshell: sufficient sleep is important for health. But what exactly happens during sleep? We briefly summarize some sleep phases.

The most important sleep phases in brief

Fall asleep phase

The phase of falling asleep is characterized by a general relaxation and a feeling of coming to rest. Pulse, breathing and blood pressure relax. The muscular relaxation is noticeable for many people by an uncontrollable muscle twitching. Sleep is still rather superficial a few minutes after falling asleep, so that small disturbances can lead to waking up again or to disturbances of sleep.

Light sleep phase

The phase of falling asleep is followed by a phase of light sleep. In this phase, the brain processes the day's information, the muscles relax further, and the vital parameters are lowered further. Most people spend about half of their sleep in this phase.

Deep sleep

In this phase of sleep, we are less sensitive to noise and therefore difficult to wake up. If we are nevertheless awakened from this phase, we are dazed and clouded and must first get ourselves together before we are fully conscious. In the deep sleep phase, our body is shut down to a minimum, both breathing, pulse and blood pressure as well as brain activity.

Dream sleep phase / REM phase (Rapid Eye Movement)

Rapid eye movement (REM) phase is a phase of intense dreaming. We dream in other sleep phases as well, but the REM phase is particularly intense dreaming phase. To prevent us from hurting ourselves by uncontrolled movements during this intense dreaming phase, when our brain is very active, our muscles are paralyzed during this sleep phase. Many people have an experience that when they have a nightmare, they wake up and the paralysis continues for a while. This often leads to further anxiety, because the feeling of not being able to move often leads to further anxiety.

In order for sleep to be restful, the deep sleep phases are particularly important. If you don't get enough sleep, or if this sleep cycle is disturbed, you won't get the rest you need. Typical disturbances are that the first phase, the falling asleep phase is excessively long. One reason for this can be that you don't get enough rest when falling asleep, that you can't relax due to stimulating drinks - e.g. coffee and much more.