Anyone struggling with sleep problems for days, weeks or even months knows how important a healthy and restful sleep is for the overall well-being and health in general. If we do not rest well, our focus diminishes as does our ability to work under pressure and we may suffer from bad temper both at work and in private life. Even not directly affected by such experiences, one can easily imagine how it feels to be affected by sleep disorders. There may be at least one person from your family, friends or work colleagues acquainted with sleep problems. According to the German Association for Sleep Disorders and Sleep Medicine, 10 percent of the population in the Western industrialized countries suffer from sleep disorders; in fact, according to scientific researchers, at least every third person is affected by sleep difficulties.
But why is sleep so important? What exactly happens with us during sleeping? What are the causes and effects of sleep problems and how can they be effectively countered?
We are spending asleep about a third, and therefore a significant part of our lives. But it has to do not only with our need of sleeping, it is our body that asks for it. Whether as a child, young person, in our middle or old age, we know that when we sleep too little we feel drained, tired and unable to focus. A long sleep guarantees a fit shape and an awake mind. It is necessary to take the time to process the experiences we live and the things we learn, giving our body enough time to recover and strengthen. If we sleep too little in the long run, our physical and mental health can be seriously affected.
Those who sleep sufficiently strengthen their immune system and give the body time to regenerate
While awake, the cardiovascular system works at full speed. During sleep, the body takes a "pause for breathing" and our body functions are slowed down. During sleep, our breathing and heart rate, temperature and blood pressure drop. Growth hormones are released and our body uses this time to regulate the metabolism, to activate the immune system and cell renewal. Those who sleep sufficiently do not only keep themselves healthy but also prevent premature aging processes. Anyhow, we are not completely "inactive" while we sleep. It is a very dynamic process during which cyclically recurring phases alternate, causing the depth of our sleep mode to differ as well.
From active to inactive phases and vice versa. What happens when we sleep?
During the falling asleep (half asleep) stage, we drift from the state of being awake to asleep. Our perception of the environment diminishes, our muscles start relaxing and the body gradually comes to rest. Our brain waves slow down and both pulse and breathing are more regular. The length of the sleep phase depends on the individual and the day, lasting between 5 to 30 minutes. In total, falling asleep and waking phases account for about 10 percent of our sleep. After falling asleep, the light sleep begins (Stages I and II). Our muscles are rapidly relaxing, body temperature is dropping and the heart and respiratory rates are steady. We dream in this sleep stage only very rarely. However, the dramatic psychological conflicts we experience during the day return during the light sleep as realistic dreams and if very intense can prevent us from reaching the next stage of sleep and a restful sleep in general. During the night, we spend about half of the total amount of sleep time in the light sleep phase. Only in the deep sleep phase (Stages III and IV) the actual regeneration of the body, which has now come to rest completely, can begin. Our muscles are relaxed and the eyes barely move under the eyelids. Blood pressure drops heart rate and breathing slow down. In the absence of new sensory and environmental impressions, the information gathered during the day is stored in the short- and long-term memory, connecting with existing memories. In deep sleep, we almost never dream. And if, then we do so in the form of thoughts instead of images. Our first deep sleep phase can last up to an hour. However, as the sleep duration increases, the deep sleep phases shorten up to 10 to 20 minutes. Therefore, for the regeneration process and the restoration of our overall body and mind performance, the first three hours and the herein included long deep sleep phases are the most important. Once we have reached a deep sleep phase, it will be hard to wake us up. And if somebody or something is capable of doing so, we will find ourselves very likely in a state of disorientation. Overall, about 20 percent of our sleep is spent in deep sleep. After the deep sleep phase follows the fast-moving REM (Rapid Eye Movement) sleep (Stage v), which is a very active phase for our brains. While the eyes roll partly violently under the closed lids, the rest of the muscles are almost paralyzed. At the same time, heart and respiratory rates increase, becoming more irregular. At this stage, we dream and process the events and impressions of the day. Especially during the REM stage of the first sleep cycles, we process the experiences and emotions of the day in the form of dreams. Only towards the end of our sleep, dreams slip smoothly into the imagination stage. When REM sleep is over, we have gone through a sleep cycle of approximately 90 minutes and the next sleep cycle may begin.
How many hours of sleep do we need?
The number of sleep cycles that have to be completed for achieving a healthy and restorative sleep differs from person to person. One may need a lot of sleep, while another feels well rested and fully powerful only after a short sleep duration. However, usually, four to six cycles are needed in order to achieve a healthy sleep. Generally, an adult needs 6 between 9 hours of sleep to completely recover and regenerate, whereby women are sleeping on average one hour more than men.
How much sleep we actually need is influenced by multiple factors. How old are we? What is the extent of physical activities spent every day? Do we have a lot of new impressions and knowledge to process? Or does our body struggle with infections or diseases? Since the need for sleep varies from person to person and is influenced by a variety of factors, there is no PERFECT sleep duration. It is important that the first few hours of our long deep sleep phases are not bothered.