Why do people fall asleep more quickly when it rains?
Why do we strongly want to sleep when it rains? It is painful for people to go to work in such a situation. Some researchers had already studied this phenomenon. Now, let us see why it is so.
Increased negative ion content in the air
The negative ion content in the air increases when it rains. lightning and the friction between rain and air can produce a large amount of negative ions in a rainy day.
The increase of negative ions can significantly improve the human nervous system, cardiovascular system, blood system, and respiratory system. People will feel more comfortable. What’s more, the negative ions have the effect of calming and hypnosis. It is one factor which help people fall asleep easily.
Rain sounds are lullaby
Rain sounds is a rhythmic ticking sound, which sounds like a wonderful lullaby that can help people fall asleep quickly.
Studies have found that when rain sounds enters people’s brain, brain unconsciously relaxes and produces alpha waves, which are very close to the state of brain when human sleeps.
Rain sound is generally between 0 and 20 kHz. It is not upsetting. On the contrary, this sound makes people comfortable. However, if there is a sudden sound of thunder in the middle of rain sounds, it will make people stressful. At the same time, the level of cortisol in people’s body will be high.
Decreased oxygen content in the air
Oxygen can stimulate the brain and make us feel refreshed. When it rains, there is more water vapor in the air, it results in lower air pressure and a relative decrease in oxygen content. In such a situation, brain begin to slack off, and people will feel sleepy.
Increased secretion of melatonin
Human brains can secretes a sleep-related hormone, melatonin, which is secreted in the dark or when the light is dark. In the rainy days, dark clouds block the sun, and the environment becomes dim. At this time, the secreted melatonin by brain increases, making people sleepy.
At the same time, a sleep-related protein are also produced by our eyes. It is interesting that the brighter the light is, the less the protein will be synthesized. On the contrary, the darker the light is, the more the protein will be synthesized. It is sure that soon sleepiness is coming.
Human activities are restricted
When it rains, there is a limitation on people’s activities. Many outdoor exercises can’t be done. For people who has nothing to do, sleeping is probably a good choice. Everyone like comfortable state, and sleep is a kind of enjoyment.
Even though people can fall asleep easily when it is rain day, it doesn’t mean that people can enjoy a high quality of sleep because when it rains, there are lesser oxygen in air. After people wake up from a long sleep, people will still feel weak and sleepy. And when it rains, people also need to spend much more time to get out of bed.
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