In the impression of many people, the sleep of the elderly has two characteristics: one is to go to bed early and get up early, and the other is to sleep less.
Don't old people need so much sleep? How long is the best sleep time for people of different ages?
Should I sleep less when I am old?
No! According to the latest research recommendations of the American Sleep Foundation:
Older people over 65 sleep 7-8 hours a day;
18 ~ 64 adults sleep 7 ~ 9 hours a day.
This kind of sleep is easier to maintain physical and mental health than peers who sleep too little or too much.
Many people think that it is normal for people to sleep less when they are old, which is not correct. In fact, the elderly have many needs for sleep. Most elderly people lack sleep because of physiological and pathological reasons.
Possible reasons are:
1. Older people sleep shallower.
The most classic sleep regulation theory holds that people's sleep behavior is influenced by two systems in the brain, one of which is the "sleep/awake balance system".
After waking up, people will constantly increase their tendency to sleep, and they are the most sleepy at night;
During sleep, the tendency to wake up is increasing, and it begins to wake up in the morning.
But most old people are not so sleepy.
They don't feel sleepy at night as they did when they were young. Why, their nightlife is generally simple and they are used to going to bed early. As a result, the driving force of sleep is insufficient, but once you go to bed, you can't sleep.
In addition, due to the increase of age, the deep sleep of the elderly decreases and the shallow sleep increases accordingly. Moreover, they are more sensitive to environmental factors (such as sound) and easily wake up from shallow sleep.
Wake up more times, will lead to less total sleep time, sleep quality decline.
In the long run, many elderly people feel sleepy during the day and will use naps and naps to make up for their sleep. If the make-up time is too long, the driving force of sleeping at night will be continuously reduced, and there will be more and more drowsiness, resulting in a vicious circle of "less sleep".
2. Affected by the biological clock, leading to getting up early.
Another thing that affects sleep in the brain is the "circadian rhythm system", which is what we often call the "biological clock". The body will make corresponding physiological and behavioral adjustments according to the local day and night changes.
Body temperature, melatonin and cortisol are important factors affecting circadian rhythm.
The study found that among the elderly, these three rhythms are about an hour earlier than those of young people.
For example, the body temperature of ordinary young people reaches its peak at 22 o'clock in the evening, and then it begins to drop, and the body begins to prepare for sleep. The body temperature of the elderly began to drop from around 2 1 at night, or even earlier. The same is true in the morning. The temperature of the elderly is basically one hour earlier than that of the young.
The change trend of melatonin and cortisol is similar to body temperature.
Light is another factor that affects people's circadian rhythm.
Some studies believe that the elderly lack outdoor activities. Moreover, the degradation of the eye itself will also reduce the light received, thus affecting its own circadian rhythm.
3. Effects of diseases
The growth of age has brought about changes in various physiological systems, even for the completely healthy elderly, sleep will be reduced accordingly.
However, many elderly people are not completely healthy, and the influence of diseases on sleep is far greater than physiological factors.
At least half of the elderly will be affected by these diseases when they sleep, such as:
Sleep disorders: insomnia, obstructive sleep apnea, periodic limb twitch disorder;
Chronic pain and cardiovascular diseases;
Nervous system diseases: Alzheimer's disease, Parkinson's disease and so on.
In short, it is not normal for the elderly to sleep less, and it is not conducive to health. If it affects their daily life during the day, we must pay attention to it.