Medically Reviewed by Dr. Elisabeth Vincent Hamelin
Sleep is needed for your body and your brain to recover and process impressions. When you sleep at night, you can more easily cope with stress and stress during the day. Sleep can also reduce the risk of illness.
This text is about sleep and health. You can also read the text Sleep difficulties and Children and sleep.
What happens when you sleep?
Sleep is needed for the body and brain to recover and process impressions. During sleep the body relaxes, blood pressure drops, the heart rate and body temperature go down, the breath becomes less and the muscles relax. In parts of the brain, activity decreases. At the same time, memories are stored and new knowledge and new impressions are processed.
When you sleep, the body’s immune system is activated and important hormones are formed. At the same time, the production of stress hormones decreases. Sleeping adequately can reduce the risk of diseases such as elevated blood fat, cardiovascular disease, type 2 diabetes, depression and fatigue syndrome.
For children and adolescents who grow up, sleep is of great importance because growth hormone is then formed.
The need for sleep is different in different people
Adults usually need between six and nine hours of sleep per day. But it varies from person to person. It also varies depending on how effective your sleep is, that is, how much deep sleep you have received.
As long as you are feeling well and working well during the day, you will get enough sleep. On average, adults sleep about seven hours a day. Infants and teens need more sleep. A newborn baby sleeps about 20 hours a day. Then, the need for sleep decreases with age, except for a temporary increase during adolescence. Teenagers usually need to sleep eight and a half to nine hours a day and 60-year-olds usually sleep about 6 hours.
Sleep is divided into different stages of sleep
Sleep is divided into so-called sleep cycles of about 90 minutes. During a sleep cycle, sleep alternates between different stages of sleep.
The different stages of sleep are as follows:
- Falling asleep. In this phase, sleep is superficial and you are easily awakened.
- The base sleep, the so-called normal sleep.
- Deep sleep. In this phase, the body’s recovery and build-up takes place. The brain works more slowly and the production of stress hormone decreases. During deep sleep the muscles relax and you are difficult to wake. If you are awakened in this phase, you may feel confused and it will take time before you feel awake.
- The dream sleep which is also called REM sleep. REM stands for rapid eye movement which means rapid eye movements.
When you lie down, the lamp goes out and starts feeling drowsy, the alertness drops. Then you are in the sleep phase. Then you get into the base sleep and afterwards you get into the deep sleep.
Bass sleep and deep sleep recur regularly during the night along with periods of dream sleep. At the beginning of the night, sleep is dominated by deep sleep. Thereafter, the periods of deep sleep become shorter and the periods of dream sleep longer. Dreams occur during the various stages of sleep, but they are most common during REM sleep. Then the brain works actively in a way that is reminiscent of when you are awake.
Deep sleep is important for the body’s recovery
In order for the body and the brain to have sufficient recovery, you need to get enough of the deep sleep. The longer you have been awake, the deeper your sleep becomes. It is also easiest to sleep and get deep sleep when the body’s internal clock is set to night and the body’s metabolism is low.
The older, the more easily awakened
As you get older, deep sleep decreases and you sleep more superficially and wake up easier.
Women may notice the change associated with menopause. Sleep can be affected by sweats at night, but also by sleepiness.
When you can’t sleep
The vast majority have ever experienced a sleepless night because of stress or anxiety. It’s hard not to be able to sleep a few nights, but it’s not dangerous. When that happens, the body can cope with the lack of sleep next night.
If sleeping difficulties persist, it is important to consider the causes as soon as possible. It can be more difficult to cope with sleep problems the longer it goes.
When you do not get a good sleep, you work worse than usual in several ways. Then it is a little harder to cope with work and everyday stress. The immune system is also impaired by a lack of sleep, which makes it easier for you to get sick. Too little sleep also affects the brain’s center of satiety and hunger so you can feel hungry. Sleep deprivation also affects the blood sugar balance and can make you extra craving for sweets.