Why does rain make us sleepy?

There are mornings or afternoons when it's drizzling, the alarm clock rings but our bodies don't bother to move.

When it rains, the body will feel sleepier - Photo created by AI

Feeling lazy, lethargic or just wanting to stay in bed when it rains is not really a personal emotion, but stems from very specific physiological reactions in the body.

According to IFL Science , science has shown that rain significantly affects the functioning of the nervous system, hormones, and living environment, all of which can make us feel sleepier than usual.

Rain "indirectly" reduces serotonin and increases melatonin

Sunlight plays a particularly important role in regulating the human biological clock.

UVA and UVB rays from sunlight stimulate the body to produce serotonin, a hormone that increases alertness, improves mood, and enhances concentration. At the same time, light also reduces the production of melatonin, a sleep-inducing hormone secreted by the pineal gland at night.

However, on rainy days, the sky is gloomy, the clouds are thick and the light is greatly reduced, the body automatically "misunderstands" that it is time to sleep. At this time, the amount of serotonin decreases, while melatonin increases, making us easily fall into a state of lethargy and fatigue.

Dr. Darius Loghmanee, a sleep specialist at Advocate Christ Medical Center (USA), explains: "Human ability to sleep or wake up is governed by the environment. If you are used to sleeping in the dark, having light in the room can make it difficult to fall asleep. Conversely, if you are used to waking up in the light, dark days or winter can make it very difficult for you to stay awake."

The body spends more energy

Rain also creates a humid environment. As humidity increases, the body must work harder to maintain a stable body temperature through the process of homeostasis. This regulatory process consumes energy and contributes to feelings of fatigue.

In addition, rain often causes a drop in atmospheric pressure, especially during thunderstorms or typhoons.

Low pressure means there is a slight decrease in the amount of oxygen in the air. Although this change is small, it is enough to affect the body's ability to exchange oxygen, making some people feel more tired and lethargic than usual.

The sound of falling rain is also a type of sound that helps you sleep easily - Photo: TAYLORFINN0810

The sound of rain helps you sleep

In addition to the effects of light and the environment, the sound of rain itself also affects the brain.

The steady, gentle sound of falling rain is a form of "pink noise," a low-frequency, soft, natural background noise that is different from "white noise," which is higher-frequency and harsher.

Pink noise has the ability to calm the nerves, mask distracting noises, and aid in the process of falling asleep. In addition to rain, the sound of wind blowing, rustling leaves, and heartbeats are also forms of pink noise.

Some studies show that listening to “pink noise” at night can help improve sleep quality, increase depth, and reduce the number of awakenings.

Seasonal affective disorder (SAD)

Many people experience low mood, difficulty concentrating or prolonged fatigue on days with little sunlight, especially in winter.

This phenomenon is called SAD - short for Seasonal Affective Disorder.

Essentially, SAD is a form of cyclical depression, caused by a lack of light disrupting circadian rhythms and reducing serotonin levels in the brain.

Although SAD is common during the cold season in temperate countries, mild symptoms can also appear during long rainy spells in the tropics.

To improve this condition, doctors often recommend light therapy. Specifically, the patient sits in front of a specialized light box with an intensity of 10,000 lux for a certain period of time each day, simulating the effect of sunlight.

According to Dr. Michelle Drerup - director of the Center for Behavioral Sleep Medicine at Cleveland Clinic (USA), light box therapy not only helps improve SAD but is also useful in combating the feeling of prolonged sleepiness during the day, also known as "sleep inertia".

What to do to "resist" sleepiness on rainy days?

There are still simple ways to help your body overcome this state of fatigue.

A little light exercise, such as walking around the house or doing some stretching exercises, can help increase blood flow, improve mood, and wake you up. Turning on the lights in the room on cloudy days can also help your body clock to function properly, avoiding a persistent feeling of sluggishness.

Besides, maintaining the habit of sleeping on time, drinking enough water and limiting dependence on coffee are small habits but have a significant impact on energy during the day.

Although rainy weather can make your body want to rest, with a few reasonable adjustments, you can completely maintain a stable pace of life and gently overcome gloomy days.

HOANG THI

Source: https://tuoitre.vn/vi-sao-troi-mua-khien-ta-buon-ngu-20250603130018636.htm