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"I feel unwell during seasonal changes," "I feel like I can't sleep well anymore." You've probably felt this way during seasonal changes, haven't you?
Indeed, there's a common understanding that one tends to get sick easily during seasonal changes.
However, many people have this vague awareness but don't know the root cause.
So, this time, we'll teach you methods to prevent colds during seasonal changes and achieve sound sleep.
We will also explain the causes of colds and bodily functions.
Reading this article will clear up any questions you've had until now!
1. Is poor sleep to blame for catching colds easily during seasonal changes?
During seasonal changes, colds can worsen due to temperature differences, but did you know that in many cases, sleep is the cause of "sore throats" and "fatigue"?
While sleeping, macrophages, which act as an immune function, become less active, and the body's immune function declines, reducing resistance to invading viruses.
Especially, people with a habit of mouth breathing often have dry throat mucous membranes, leading to a higher incidence of colds upon waking.
1-1. The majority of colds are caused by viruses.
80-90% of pathogens that cause colds are viruses.*1
While there are various viruses such as rhinovirus and coronavirus, general bacteria and special bacteria like Mycoplasma pneumoniae can also be the cause when they invade the body.
Especially if your bedroom is dry and airborne viruses can easily attach to the mucous membranes of your mouth or nose, bacteria and pathogens can attach to your body while you sleep, leading to nasal congestion and sore throats.
In other words, if you can take measures against the viruses that cause colds, you can avoid catching a cold even during periods of extreme temperature differences.
1-2. Temperature fluctuations can also lower sleep quality.
Changes in climate and environment, specifically temperature differences, can reduce sleep quality.
During seasonal transitions with fluctuating temperatures, changes in morning and evening temperatures and shorter daylight hours can lead to earlier sunrise times, resulting in shallower sleep and often insufficient sleep.
Additionally, melatonin, the sleep hormone that induces drowsiness, decreases in secretion when the night is shorter, which can hinder falling asleep and reduce sleep quality.
Furthermore, drastic temperature changes can make it difficult to regulate body temperature during sleep, causing fluctuations in body temperature that can lead to colds or a feeling of sluggishness.
2. Defenses are prone to weakening during seasonal changes in sleep.
During seasonal changes, the body's defenses tend to weaken during sleep, making one more susceptible to illness.
During the day, when saliva secretion is active, the body has a strong defense against viruses entering the mouth, and swallowed viruses are killed by stomach acid, making it relatively difficult to catch a cold.
However, during sleep, brain and body functions are suppressed to a minimum, so the mucus that prevents infection from pathogens is not sufficiently secreted.
During sleep, the mouth dries out, and the amount of mucus secreted decreases, which weakens the body's defenses and makes it harder to protect against colds.
However, please understand that this decrease in defense does not mean a drop in immunity, but rather a lowered defense against viral attacks.*2
2-1. Nose and throat tend to dry out
Everyone has experienced a sore or scratchy throat upon waking up. This is especially true for those who tend to breathe through their mouths with their mouth open, as they are more likely to experience such symptoms upon waking.
During sleep, moisture evaporates from the body, and the nose and throat tend to dry out, so caution is necessary. A dry mouth reduces saliva secretion, making it easier for airborne pathogens and viruses to spread through airborne transmission.
Also, viruses can easily infect through slight openings, such as touching the nose or mouth while tossing and turning or during sleep, leading to contact infection.
If you sleep with your mouth open, viruses multiply in your dry throat and airways, which can ultimately lead to illnesses like a sore throat or fever when you wake up in the morning.
2-2. The body's protective functions are also reduced to a minimum.
While sleeping, brain and body activities are suppressed to a minimum, and the body's protective functions are performed only to the necessary minimum.
"Wait, doesn't sleep boost immunity?" you might think, but many people who catch colds often do so due to lack of sleep or reduced body function.
If you're accumulating fatigue from daily sleep deprivation and an irregular lifestyle, and carrying a sleep debt, your defenses against invading bacteria and viruses will be lowered. This can make you more prone to nasal congestion, coughing, and sore throats upon waking.
3. 5 Ways to Get Good Sleep During Seasonal Changes
Establishing healthy sleep habits during seasonal changes is crucial for maintaining a regular lifestyle and a healthy body.
When there are extreme temperature differences day after day, it can become difficult to fall asleep, or to wake up feeling refreshed in the morning.
These effects negatively impact not only the body but also the mind. As a result, daily performance decreases, affecting studies and work.
Here, we will explain five methods to maintain good quality sleep even during seasons with extreme temperature differences.
These methods are easy to incorporate, so if you're experiencing sleep problems at the transition from winter to spring, or autumn to winter, give them a try.
3-1. Maintain bedroom humidity
To maintain sleep quality, it is essential to keep the humidity in your bedroom around 50%.
Maintaining a humidity of 50% helps control viral activity and promotes comfortable sleep.
To prevent colds, use a humidifier to maintain appropriate humidity.
However, if you use too much humidification and condensation forms when the temperature drops, leading to mold, that defeats the purpose.
Condensation can worsen asthma and allergies, and also cause insomnia, so place a hygrometer in your room and use a humidifier as needed to maintain the bedroom humidity.
3-2. Sleep with a mask on
Wearing a mask while sleeping is effective in preventing colds by blocking the entry of viruses during sleep.
If you sleep without a mask, with your mouth and nose exposed, moisture evaporates from your body, making your throat prone to dryness. Wearing a mask while sleeping helps keep the area around your mouth from drying out, which can prevent colds!
Additionally, it has the added benefit of moisturizing dry lips and skin, which is a bonus for women.
If you find a mask uncomfortable and can't sleep, anti-snoring tape can also prevent dryness caused by mouth breathing.
On the other hand, if you experience breathlessness or difficulty falling asleep while wearing it, do not force yourself to wear it and sleep without it.
3-3. Use an air purifier to clean the air.
By using an air purifier to clean the indoor air, the polluted air in the room is purified, leading to restful sleep. Just clean air alone can bring peace of mind!
However, if the air in the room is polluted with dust mites and dust from bedding, sleep quality will decrease, leading to difficulties sleeping, insomnia, and other physical ailments. This can ultimately have a negative impact on the body and reduce sleep quality.
Try to place the air purifier near the entrance/exit of air to remove harmful substances spreading in the bedroom before they adhere to the floor or walls.
However, some air purifiers emit light or make noise that can disturb sleep. It might be a good idea to place it further away from the bed or turn it off after purifying the air before you fall asleep.
3-4. Ventilate before bed to change the air.
With a little care, just opening the window to ventilate the bedroom before bed can change the depth of your sleep. There are even research findings that show air exchange improves sleep quality.
In fact, a study by the Technical University of Denmark reported that sleeping in a room with exchanged air and reduced carbon dioxide levels improved sleep quality and enhanced performance on logical thinking tests. *3
If you can achieve restful sleep simply by ventilating before bed and reducing carbon dioxide levels, there's no reason not to do it.
3-5. Adjust bedding according to the weather of the day.
It is also important to adjust your bedding, such as pajamas and underwear, according to the weather of the day.
During seasonal changes with temperature variations, there can be extremely cold days as well as warm days, so nighttime temperatures will differ.
Therefore, to prevent your body temperature from dropping too low while you sleep, wear slightly thicker pajamas than usual, adjust the number of blankets, and create an environment that makes it easy to maintain an optimal body temperature during sleep.
By adjusting your bedroom and bedding, you can control your core body temperature and sleep soundly until morning.
Summary: Pay extra attention to sleep during seasonal changes.
Did you understand that one of the reasons for catching a cold during seasonal changes is sleep?
It became clear that sleep is related to why we catch colds when there are temperature differences.
Perhaps the reason you had trouble sleeping on nights with continuous temperature differences, felt sluggish when you woke up, or had symptoms of a sore nose or throat was because your bedroom or preventative measures were inadequate.
Take this opportunity to review your sleep habits during seasonal transitions.
The key points of this article are as follows:
- The majority of colds are caused by viruses.
- The body's defenses weaken during sleep.
- Adjust bedroom humidity to around 50%.
- Sleep with a mask on.
- Ventilate the room before bed.
By taking appropriate measures during seasonal changes, you can improve sleep quality and prevent colds.
With a little ingenuity, you can maintain a healthy mind and body, so try incorporating new preventive measures.
【References】
※1 Doctors File "Cold"
※2 Catching colds during sleep: Countering immune decline with humidification & restful sleep
※3 The effects of bedroom air quality on sleep and next‐day performance
