During deep sleep, some of our body cells are highly active. During this time, the body processes a particularly large number of proteins to repair damage to the cells and to form new ones. Permanent too short or completely missing deep sleep phases deprive the body of the chance to regenerate and open doors for diseases of the metabolism, premature aging processes and disorders of the body’s defenses up to autoimmune disorders and cancers.
What are deep sleep stages?
Immediately after the 20-30 minute phase of falling asleep, the first deep sleep begins, which is considered the longest and most regenerative phase, lasting 30-60 minutes. Humans have five sleep phases, of which phase 3 and 4 belong to deep sleep. During this time we do not dream. In phase 1 and 2 we fall asleep or the sleep is superficial. The five sleep phases repeat up to 6 times in always the same order: phase 1, 2, 3, then vice versa 4, 3, 2, and at the end REM in each case. This happens over the 7-8 hours, which a healthy sleeper needs. A complete cycle is always about one and a half hours long. Immediately after the 20-30 minute phase of falling asleep, the first deep sleep begins, which with 30-60 minutes is considered the longest and most regeneration-intensive phase. Towards morning, the last deep sleep lasts only a few minutes. REM sleep phases, on the other hand, are longest in the morning hours. Each deep sleep phase is followed by such a REM dream phase.
Function and task
Sleep takes up one third of a human life. If this sleep is missing, we very quickly recognize consequences such as exhaustion, irritability and lack of concentration. During deep sleep, the body repairs most of the important cell associations and organs. The body’s defense system produces important immune substances. Physically active people and people with a fast metabolism usually have longer deep sleep phases, which are not considered the fountain of youth in popular parlance for nothing, as with the well-known beauty sleep. This has its justification also in the medical sense. Vital bodily functions such as muscle tension and breathing, the heartbeat, blood pressure or body temperature get out of whack if deep sleep is missing or too short. Hormones and metabolism need the natural rhythm of mindfulness and sleep, of rest and activity. Blood pressure, digestive activity and muscle tension decrease when we sleep. Especially during deep sleep, blood pressure and body temperature decrease. Growth hormones are released, which stimulate cell repair and stimulate and strengthen the defense system. At the same time, learned information and impressions are copied from short-term memory into the cerebral cortex, emptying the cache, so to speak, and making it ready for new experiences. During rest periods, relevant information is sorted and reactivated. In the morning – imperceptibly and naturally for us – the entire body system is strengthened. Deep sleep thus promotes our well-being, improves our ability to concentrate and learn, and strengthens our defenses. Deep sleep is a short vacation for body and soul. The muscles relax, blood pressure and circulation are reduced, and the stress hormone cortisol is at its lowest compared to other sleep phases. In phase 5, REM dream sleep, muscle tone is then maximally relaxed, eyes flutter and roll, and people dream. Sleep onset and light sleep phases are short, lasting a mere 10, 20, or 30 minutes.
Diseases and ailments
When there is a lack of sleep, the level of the stress hormone cortisol increases in the blood. If a person has a permanent lack of sleep or very irregular sleep duration or even times to fall asleep, this can already have a negative effect on the body’s defenses, because too much cortisol at night means permanent stress. This damages the adrenal cortex and thus directly interferes with the metabolism. As a next consequence, insulin secretion and sugar metabolism can be affected, which regulate the body’s ability to deal with glucose. In short phases of child rearing and interrupted night sleep due to illness, one already feels these effects, which regenerate as soon as the critical phase is over. However, if the condition persists, health disorders creep in. Permanent sleep deprivation can be associated with weight gain and an increased risk of developing diabetes.The total metabolic rate is reduced, glucose metabolism can be permanently disturbed, resulting in unbridled appetite, especially for high-calorie food. The vicious circle begins. After just one shift week with less than six hours of sleep at a time per night, more than 700 genes are damaged each night. Lack of deep sleep is a risk factor for obesity and many metabolic disorders. This severely disrupts harmonious body processes for maintaining an energy balance. The natural sense of appetite or hunger, the balance of energy intake and energy consumption quickly fall into the realms of diabetes mellitus type 2 when sleep deprived. When sleep deprived for a very long time, people have hallucinations, personality disorders or depression, even suicidal thoughts. In old age, on the other hand, deep sleep phases decrease quite naturally. This is not a cause for concern, as in older people the nap in between is a wonderful restorative break, and overall activity decreases somewhat. As a result, less night sleep is needed. However, if you want to be active and vibrant with maximum health into old age, you would do well to take loving care of yourself and your healthy deep sleep periods. Lack of deep sleep can have the following effects:
- Susceptibility to diabetes increases
- Obesity
- Stroke
- Autoimmune diseases and cancer
- Cardiovascular diseases
- Lack of concentration
- Affects reproduction, libido, vitality, zest for life.
- Increases sensitivity, susceptibility
- Affects emotional life
- Deteriorates skin appearance
- Increases hunger pangs, cravings for calorie-rich foods
- Weakens sense of healthy and the beautiful in life
- Depression and even suicidal thoughts.
Healthy deep sleep is the basis for health, quality of life and coping with modern life with all its stimuli and stresses.
