Healthy sleep is important for well-being and performance. At the same time, humans do not always sleep equally deeply. Within one sleep, the body goes through several sleep cycles, one of which is deep sleep.
What is deep sleep?
The human sleep rhythm can be divided into different sleep phases. After the falling asleep phase, the body enters a deep sleep phase. This begins about half an hour after falling asleep. The human sleep rhythm can be divided into different sleep phases. After the falling asleep phase, the body enters a deep sleep phase. This begins about half an hour after falling asleep. During this cycle, the electroencephalogram – EEG for short – in the sleep lab shows regular wave patterns with troughs. The first deep sleep phase is usually the longest and lasts for about an hour. Deep sleep is interrupted by lighter dreaming or REM phases. REM stands for “rapid eye movement” and refers to a phase that is very close to wakefulness. On average, the human body goes through four to six sleep cycles each night, consisting of light sleep, deep sleep and dream sleep. One cycle lasts about ninety minutes. Toward morning, the duration of deep sleep shortens. After about four hours, humans hardly fall into deep sleep. Research shows that waking up early in the morning does not affect performance, as long as the body was able to fully use the first deep sleep phase necessary for it.
Function and task
Basically, almost all of the positive effects of sleep are triggered by the deep sleep phases. Generally speaking, sleep serves the recovery and regeneration of the body. After a busy day, a feeling of exhaustion and fatigue indicates the body’s need for sleep. Reserves are replenished during the period of deep sleep. The immune system is strengthened by an increased hormone output. Muscles relax during deep sleep, while blood pressure and circulation decrease. Cortisol levels are also at their lowest during this phase. Cortisol is a stress hormone that is reduced during the deep sleep phase. In addition, learned information is best memorized during this period. Thus, the deep sleep phases not only serve the physical recovery, but also have a positive effect on the mental state. To prove this, several studies were conducted in which test subjects had to memorize patterns before going to bed. These were to be reproduced after waking up. As expected, they achieved better results than test subjects who were presented with the pattern for the first time after sleep. The events of the day are sorted in deep sleep and processed in the dream phases. In the process, the brain sorts out unimportant information and organizes negative and positive experiences. The body’s performance is ensured especially in the deep sleep phase. However, this is also the sleep phase in which people are most likely to talk or sleepwalk in their sleep. In most cases, this does not cause any disadvantages for the person. For partners, however, sleepwalking can be disturbing and unpleasant. The person affected, on the other hand, should not be disturbed during this phase. Those who are awakened in deep sleep usually show disorientation and states of confusion, as the body’s consciousness functions are completely shut down for recovery.
Diseases and ailments
Considering these aspects, it seems to be hardly surprising what effect sleep disorders can have on the human body and everyday life. Constant interruption of sleep by disturbances decisively interferes with the sleep cycles of humans. Recovery and regeneration can thus no longer be guaranteed. Affected persons are unrested and may complain of fatigue and lack of concentration. If this is the case from time to time, further consequences need not be feared. Regular sleep disturbances, on the other hand, have a negative effect on the organism. Stress, exhaustion and concentration difficulties are the result. Those affected are often more easily irritable and can no longer perform everyday tasks with the usual efficiency. In addition, physical fitness also declines. The result is fatigue. Sleep disorders are often accompanied by muscle tension, as the body is unable to relax to the necessary extent. Various complaints and illnesses occur during the sleep phases and disturb their restfulness.This includes, for example, so-called sleep apnea. This is a disease characterized by respiratory arrest during sleep. The result is daytime sleepiness and microsleep. In addition, a number of secondary diseases can be triggered by sleep apnea syndrome. The constant nocturnal awakening is caused by alarm reactions of the body due to insufficient oxygen supply. Often the waking up is not consciously perceived. Another disorder that prevents healthy sleep is narcolepsy. This is excessive daytime sleepiness associated with uncontrolled falling asleep. In addition, nighttime sleep is disturbed. In addition to a disturbed sleep rhythm triggered by everyday life or psychological causes, up to 10% of the population regularly suffer from restless legs syndrome. The disorder manifests itself in an urge to move the limbs, which is perceived as unpleasant and prevents the patient from falling asleep. This is a neurological disorder that is often not perceived as such by those affected. The disturbed sleep rhythm often also leads to a drop in performance as well as depressive moods and daytime fatigue. In most cases, medications such as sleeping pills or antidepressants provide relief. A change in sleep habits can also work wonders. Regular sleep rituals not only promote awareness of healthy sleep patterns, but also help sufferers organize their day better.
