Why do we sleep?
For centuries it was believed that sleep was a purely passive, unnecessary, time-wasting activity. We now know that our brains perform at their best during sleep. Experiences from the day are processed, learning processes initiated and saved. The rest of the body is put on the back burner at the same time. Circulation, breathing and pulse are slowed down. Sleep is essential for development, well-being and health. Sleep is not a steady state. Different sleep phases (light, medium deep, deep sleep and dream sleep) are run through during the night. These alternate again and again. Deep sleep is primarily used to relax the body. The focus is on the maintenance and repair of our organs. Sufficient deep sleep prevents or slows down the aging process. The mental recovery then takes place in dream sleep (REM sleep). If subjects were deprived of REM sleep under test conditions - for example by constant waking - then they developed a depressive and aggressive mood.
How much sleep is necessary?
The average sleeping time in Germany is about 7 hours. We spend about 1/3 of our life “while sleeping”. However, most people sleep too little. Everyone has an individual need for sleep that is best to find out. Holidays are a good way to do this. Always go to bed evenly in the evening and do not set an alarm clock for the morning. You shouldn’t get up until you feel awake and sleepy. Then make a note of how long you slept each night. Thus you determine your personal need for sleep. If you can concentrate on your daily work during the day, even while doing long activities, without getting sleepy, you have found your personal sleeping quota. Most people will need between seven to eight hours of sleep. Newborns, babies and children need more sleep than adults. By the way, you can catch up on sleep while “sleeping in” unfortunately does not work.
Sleep changes in old age
Sleep changes with age. Sometimes this change with age is difficult for the sleep physician or for those affected to differentiate from pathological changes as part of an aging process. Not only sleep changes, but also the day-night rhythm. Older people usually go to bed earlier and wake up earlier. Changing living conditions can be a reason for this. However, the widespread view that older people need less sleep than younger people is wrong. The age-specific changes in sleep can usually be more easily compensated for by the mostly freely configurable daily routine of older people. While infants still sleep up to 16 hours a day, this decreases over childhood and adolescence. Babies have up to eight hours of dream sleep, while adults only sleep about 1 - 1 1/2 hours a night. Deep sleep phases also decrease with age, while the time to fall asleep increases especially from the age of 40.