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The disease where allergic symptoms like sneezing, runny nose, and nasal congestion appear during the pollen season of plants such as cedar and cypress is called "hay fever (allergic rhinitis)." Many people likely use oral medications, nasal sprays, and eye drops to alleviate hay fever symptoms.
However, even when taking medications with fewer side effects, one might often feel sluggish during the day or be overcome with sleepiness.
This article explains the causes of drowsiness due to hay fever and how to cope with it for those experiencing such troubles.
Why do I feel sleepy during hay fever season?
The timing of pollen dispersal varies depending on the type of plant, but for cedar pollen, which is a major cause of hay fever in Japan, the peak season is typically from February to April.
During the season of heavy cedar pollen dispersal, many people likely feel "sleepier than usual."
Various reasons can be considered, and one of them is "disruption of the autonomic nervous system." Early spring is a period of drastic temperature changes, making it easy to experience sleepiness and fatigue due to autonomic nervous system imbalance.
The autonomic nervous system, which is closely related to sleep, is divided into two types: the sympathetic nervous system, which becomes dominant when the body is active, and the parasympathetic nervous system, which becomes dominant when the body rests. They balance each other to regulate the body. It is believed that the drastic temperature changes in early spring disrupt this balance, leading to increased feelings of sleepiness and fatigue.
Additionally, other causes of sleepiness include:
- Hay fever symptoms
- Effects of hay fever medication
Can hay fever symptoms make you sleepy?
Hay fever symptoms are a combination of allergic rhinitis and allergic conjunctivitis. Sneezing and runny nose occur immediately after pollen enters the nose, followed a little later by nasal congestion.
It is thought that these symptoms can lead to a lack of oxygen or insufficient sleep, resulting in daytime drowsiness.
Sleepiness due to lack of oxygen
When the nasal mucous membranes become inflamed and swollen, the nasal passages narrow, reducing the amount of oxygen that can be inhaled, which naturally leads to mouth breathing. However, mouth breathing reduces the amount of oxygen that can be taken in.
Moreover, dryness of the throat makes pollen more likely to adhere, worsening inflammation and further reducing the amount of oxygen that can be inhaled, creating a vicious cycle. As a result, a lack of oxygen to the brain is said to cause daytime sleepiness.
Sleep deprivation due to hay fever symptoms
Those with severe hay fever symptoms may have experienced difficulty falling asleep or waking up during the night due to a stuffy nose making breathing difficult, a constant urge to blow their nose, or incessant sneezing. Insufficient sleep prevents the body from recovering, leading to daytime sleepiness.
Furthermore, some individuals experience negative impacts on their work and daily life, such as difficulty concentrating or feeling sluggish, due to various hay fever symptoms.
Can hay fever medication make you sleepy?
To understand why hay fever medication makes you sleepy, it's necessary to know how hay fever works and about "antihistamines," which are often prescribed for hay fever.
Mechanism of hay fever (seasonal allergic rhinitis)
Allergy is a state where the body overreacts to antigens (foreign substances such as pollen, house dust, mites, food, animals, metals) from outside in an attempt to eliminate them. Although antigens themselves are harmless, under certain conditions, a chemical mediator called "histamine," released from mast cells, binds to "histamine receptors" in the body, causing an allergic reaction.
When an allergic reaction occurs in the nose, symptoms such as runny nose, nasal congestion, and sneezing appear. When an allergic reaction occurs in the eyes, symptoms such as itchy eyes and a foreign body sensation appear.
How antihistamines work
"Antihistamines" work by blocking the binding of "histamine," the chemical mediator that causes allergic reactions, to "histamine receptors" in the body, thereby suppressing the action of histamine (antihistamine effect).
However, histamine receptors also have the effect of activating brain function, so when antihistamines bind to histamine receptors, brain function decreases, which can lead to side effects such as drowsiness and dizziness.
Particularly in the first few days after starting antihistamines, blood concentration rises sharply, making drowsiness and dizziness more likely to occur. After taking them continuously for several days, blood concentration becomes stable, and symptoms become less likely to appear.
What happens if you don't take hay fever medication?
It is not uncommon for people to consider stopping their medication, thinking, "My symptoms are mild today," or "I have an important appointment and don't want to feel sleepy."
However, if there is a period when hay fever medication is not taken, symptoms may worsen on days with high pollen counts, or the medication may not be very effective against worsened symptoms.
If you have started taking antihistamines, continuing to take them regardless of the severity of symptoms or sleepiness is key to suppressing hay fever symptoms.
Hay fever sleepiness countermeasure 1: Pay attention to pollen inhalation and hay fever medication
To prevent sleepiness, basic hay fever measures are important. I will explain based on the Ministry of Health, Labour and Welfare's "Hay Fever Countermeasures for FY2010."
Don't inhale pollen
First, it is important not to inhale "antigens = pollen," which cause allergic symptoms. For those with hay fever, and even those who do not currently have hay fever, avoiding inhaling excessive pollen will prevent future onset.
Use masks or nasal masks
To avoid inhaling pollen, using face masks or nasal masks is effective. Wearing a mask is said to reduce the amount of pollen inhaled by one-third to one-sixth, and non-woven masks are said to be more effective at blocking pollen than cloth or polyurethane masks. Additionally, wearing a mask that fits your face size can prevent pollen from entering through gaps.
Reduce time spent outdoors
On days with high pollen counts, reduce the time spent outdoors. Days with high pollen counts are typically warm and sunny days, dry and windy days, the day after rain, or after 2-3 consecutive warm days. Be especially careful around March, as this is the peak season for cedar pollen.
It is also known that pollen dispersal is high around noon and in the evening, so it is advisable to avoid these times when going out.
Don't let pollen attach or bring it indoors
To prevent pollen inhalation, it's also important not to let pollen attach to you or bring it into your room.
Prevent pollen from adhering to your body
When pollen adheres to the eyes, it causes itching and redness, so wearing glasses is effective. The amount of pollen entering the eyes is said to decrease by about 40% with regular glasses compared to not using them, and by about 65% with pollen-specific glasses that have protective covers.
Also, contact lens irritation can worsen allergic conjunctivitis, so use glasses during pollen season.
Reference: Pollen Environmental Health Manual | Ministry of the Environment
Remove attached pollen
To remove pollen that has adhered to your body, basic virus prevention measures such as handwashing and gargling are also effective.
For pollen attached to the nasal mucous membranes, nasal irrigation with saline solution is recommended. However, avoid cold water or tap water, as they can be irritating and worsen rhinitis.
If your eyes are itchy, wash your face to remove pollen around your eyes, or rinse out the pollen with eye drops that are similar in composition to tears.
Furthermore, it is said that antigens such as pollen can also enter through the skin and cause allergies. Since the skin's barrier function weakens when it dries, be sure to moisturize thoroughly.
Don't bring pollen into the room
The likelihood of pollen adhering varies depending on the fabric of clothing. Generally, wool is more prone to pollen attachment than cotton or synthetic fibers, so for outerwear, smooth materials are recommended instead of wool.
To further prevent bringing pollen into the room, brush off pollen at the entrance and take off your coat around the entryway. Pollen also adheres to hair and face, so taking a shower and changing clothes immediately after returning home can prevent pollen from spreading throughout the room.
Additionally, prevent pollen from adhering to laundry by drying clothes indoors or using a dryer or bathroom dryer.
Use hay fever medication that doesn't cause drowsiness
As mentioned earlier, when histamine receptors, which have the effect of activating brain function, bind to antihistamines, brain function decreases, inducing drowsiness. However, many non-drowsy medications are now available, so choose ingredients that suit your lifestyle.
For those who wish to improve with oral medication, second-generation antihistamines are recommended. Various second-generation antihistamines are available over-the-counter, including fexofenadine, cetirizine, epinastine, and ebastine. Nevertheless, they do not completely eliminate drowsiness, so if you absolutely want to avoid sleepiness, you might consider herbal medicine. Furthermore, with nasal sprays or eye drops, there is almost no concern about drowsiness.
If you are unsure which medication is suitable for you, it is recommended to consult an ENT doctor rather than self-diagnosing.
Get quality sleep
To prevent daytime sleepiness, it is important to get quality sleep. Many people may not be able to sleep due to nasal congestion during pollen season. In such cases, promoting blood circulation in the nose and around the eyes is said to alleviate symptoms.
Brain Sleep offers an eye mask that improves sleep quality during pollen season. It is washable and features a special anti-static treatment, making it less likely for indoor pollen to adhere. It also comes with hot and cold gels, allowing for versatile use depending on the situation.
Brain Sleep Eye Mask Hot + CoolHay fever sleepiness countermeasure 2: Improve your sleeping environment
Since hay fever symptoms can prevent deep sleep, it's also important to optimize your sleeping environment.
The "Guidelines for Sleep for Health Promotion 2014" published by the Ministry of Health, Labour and Welfare's Health Bureau states that room temperature, humidity, and bed temperature affect the onset and depth of sleep, and that the quality of sleep is also influenced by bedroom lighting before bedtime and the sound environment during sleep.
Room brightness (light)
Melatonin, a hormone that promotes sleep and is secreted at night, has its secretion suppressed when exposed to high-intensity light, awakening the brain and hindering smooth sleep onset. Therefore, avoid strong light for an hour before going to bed.
Furthermore, before falling asleep, warmer light tones like orange, which have a lower color temperature, are said to be more relaxing than cooler light tones like white or blue, which have a higher color temperature. If you find it difficult to sleep in complete darkness, it is recommended to adjust by placing indirect lighting away from your face.
Sound
According to the WHO's Environmental Noise Guidelines for the European Region (2018), a sound environment of generally 40 dBA (decibel A) or less (the moderate quietness of a library) is desirable for sleep. Sounds above 0 dBA affect sleep, and at 50 dBA or more (the noise level of an extractor fan), half of people are said to have their sleep disturbed.
Furthermore, sleeping with the TV or radio on can awaken the brain and degrade sleep quality. Therefore, when sleeping, block out noise from outside the house and turn off the TV and radio. In a dark, silent environment with less sensory stimulation, arousal levels can increase, making minor sounds bothersome or increasing anxiety and tension, making it difficult to sleep.
If small noises from appliances bother you and prevent sleep, it's recommended to play healing music for sleep and set a timer for it to turn off.
Bedding
Choose a mattress and pillow that suit your body type and sleep concerns, and consider the feel, lightness, and warmth of your duvet. Additionally, choosing bedding with excellent moisture absorption and release can prevent moisture buildup and lead to quality sleep.
Furthermore, wearing pajamas that improve sleep quality, rather than ordinary T-shirts or sweatpants, is important. Pajamas are free of unnecessary embellishments and constrictions, making it easier to turn over in bed.
Room temperature
The ideal room temperature for a bedroom is around 25-27 degrees Celsius in summer and 15-18 degrees Celsius in winter, with a year-round humidity of 50-60%. Furthermore, a bed temperature of around 30 degrees Celsius and humidity of around 50% are considered comfortable.
When falling asleep, drowsiness is promoted by a drop in core body temperature, so pay attention to indoor temperature and humidity. If the temperature is too low or too high, the core body temperature will not drop, leading to difficulty falling asleep and an increase in awakenings during sleep, which can degrade sleep quality.
Also, since outside temperatures differ between summer and winter, adjust your sleep environment by effectively using bedding, air conditioning, and humidifiers for each season.
References
Guidelines for Sleep for Health Promotion 2014 | Ministry of Health, Labour and Welfare
Effects of thermal environment on sleep and circadian rhythm | Kazue Okamoto, Wataru Mizuno
Sleepiness due to hay fever can be prevented!
There are multiple ways to prevent hay fever. Try various methods to find what works for you and manage your hay fever effectively.
Furthermore, improving overall sleep quality is beneficial even outside of hay fever season, so perhaps consider enhancing your sleep environment and exploring products that support sleep at this time.
Hay fever sleepiness countermeasure 3: Incorporate products that support sleep environment improvement
To achieve comfortable sleep, it's also necessary to optimize your sleep environment. Here, we introduce products provided by Brain Sleep that can support your sleep environment. Incorporate them wisely and get comfortable sleep even during hay fever season.
