It's windy outside, don't you want to get up in bed anymore?
Even if you lie in bed, there are still many people who will enter the "hibernation period" in winter, and there is always a feeling of not waking up. Why?
Poor blood mobility in winter
Easy to get sleepy
The temperature decreases in winter, and the influence of temperature causes the body's blood pressure to be 12/6mmHg higher in winter than in summer.
There is evidence that for every 1 °C decrease in temperature, systolic blood pressure rises by 1.3 mmHg and diastolic blood pressure increases by 0.6 mmHg, which is because when the temperature drops, the adrenaline level in the human body rises, the surface blood vessels constrict to reduce the emission of heat, and the epinephrine accelerates the heart rhythm and increases the output of the heart, resulting in increased blood pressure.
Vasoconstriction leads to poor blood fluidity and reduced oxygen supply, in which case people are prone to drowsiness.
(Image source: Figureworm Creative)
In addition to the impact of temperature changes, the easy to be sleepy in winter is also closely related to the sleep regulation mechanism in our body.
There are changes in circadian rhythms
Affects sleep
People's sleep and wakefulness are regulated by two sets of mechanisms: circadian rhythm (biological clock) and sleep homeostasis.
Circadian rhythm biological clock is the timing system in the body, which makes the body's behavior and physiology present a rhythm of approximately 24 hours, and at the same time, it can be affected by external environmental factors to reset the rhythm.
Circadian rhythms are present in everyone, and the suprachiasmphalus plays an important role in the regulation of circadian rhythms.
Light shines on the retina, producing a signal that passes through the visual pathway from the retina to the hypothalamus to the suprachiasm, which receives the signal "It's daytime" and adjusts the body's biological clock to make it consistent with the clues provided by the external environment.
Entering the winter, the length of day and night changes, and the changes in the northern region of our country are even more obvious, and everyone will find that the day gradually becomes shorter, and the night gradually becomes longer. Under such a light clue, people will inevitably fall asleep in advance.
Moreover, after the reduction of the length of light in winter, the secretion of melatonin in the human body increases, and the secretion of thyroid hormones is reduced, and the changes in these hormones are more likely to make people sleepy and listless...
And when we sleep, more or less, is also regulated by genes. Some scholars have found that there is a protein called DEC2 in the body, if one of the above amino acids has changed (the 384th proline becomes arginine), people will have a "sleep less" phenotype, the average sleep time is reduced to an average of 6.25 hours per day, compared with 8.06 hours under normal circumstances.
It's not that you can't wake up
It's a different rhythm!
Due to environmental reasons, many people will be sleepy in winter, but there are also some people who seem to be sleepy when they see him, and seem to be sleepy all year round. In this case, it is possible that he has delayed sleep syndrome.
Delayed sleep phase syndrome (DSPS) is a common rhythm disorder. There are reports of an prevalence of 7% in adolescents, and 5% to 10% of insomnia patients in sleep disorder clinics complain of sleep delay.
The clinical manifestations of DSPS are characterized by:
(1) The time of falling asleep and waking up is later than the regular social work and rest time, and the daily sleep record shows that the sleep phase delay is continuously > 2 weeks and lasts for more than 1 month;
(2) The actual sleep time is about the same every day, generally after 2 a.m.;
(3) Once falling asleep, the duration and quality of sleep are still normal;
(4) Difficulty getting out of bed in the morning;
(5) Even forcing patients to follow the usual schedule of work and rest cannot advance the sleep time.
If it is an office worker or a student, forced to wake up early when he does not wake up, the symptoms are that he cannot sleep at night, and he is sleepless during the day and is not energetic!
Delayed sleep syndrome is closely related to mental disorders, and in outpatient clinics, patients with depression are the most common, and winter is also the season when seasonal affective disorders are frequent.
Seasonal affective disorder
Seasonal affective disorder, some also call it "winter depression."
The disease tends to occur at a specific time in the year, after which it generally resolves on its own, with a higher probability of occurrence in winter.
Symptoms include easy grief, sweets, weight gain, daytime sleepiness or excessive sleep, but after waking up, they still feel tired, lack of energy, and some people also show difficulty concentrating on work and difficulty getting along with people.
If you are sad in winter that is difficult to control, sleep and can't wake up, you may suffer from "winter depression", the best way is to try to maintain a regular schedule, go out to exercise, and feel the sun and air in the slightly cold air.
Although it is comfortable to stay in the warm quilt, there may be a new experience when you go out! No matter what causes the difficulty of getting up in winter, we still have to try to regulate ourselves and maintain both physical and mental health!
This article is reproduced from the WeChat public account "Science Popularization China"; this article is reviewed by Chen Haixu, deputy director of the Second Medical Center of the PLA General Hospital, and master tutor
Source: Tadpole Stave; Review Expert: Yin Tielun, Deputy Chief Physician of the Department of Neurology, Airport Branch of Peking University Third Hospital