
The causes of fatigue and sleepiness during the day are diverse. Not only lack of sleep, but also everyday factors such as meal sizes, water intake, physical activity, and caffeine consumption habits can have an effect. Most can be alleviated by adjusting lifestyle habits, but if fatigue repeats even with sufficient rest or is severe enough to interfere with daily life, the cause needs to be checked. We look at practical ways to reduce daytime fatigue in everyday life, along with cases that should not be passed off as simple fatigue.
Avoid overeating and stay well-hydrated
If you feel severe fatigue during the day, you first need to examine your meal sizes and hydration status. Eating a large amount all at once can worsen post-meal sleepiness and lethargy. Especially during daytime hours when physical activity is high, it is best to avoid overeating and eat appropriate portions. You must also consume enough water. This is because a lack of body fluids can increase fatigue and decrease concentration. Sleep medicine specialist Zubin Bham explained through the health and medical media outlet 'Health', "Large meals tend to induce fatigue and sleepiness." However, rather than pinning down a specific food or nutrient as the sole cause of fatigue, it is best to look at the overall meal size and nutritional balance together.
Take a short walk or stretch
When you feel temporarily tired during the day, moving your body lightly can also help. You do not necessarily need to do high-intensity exercise that leaves you out of breath. Activities such as briefly getting up from your seat to stretch or taking a short walk can also help reduce sleepiness and fatigue. Yasemin Tashman, a sleep medicine specialist at the Mayo Clinic, advised through Health, "Even if it's not high-intensity exercise, physical activities of moving your body can be helpful." Therefore, when you feel tired, it is good to start with activities you can do effortlessly in daily life, such as stretching or a short walk.
Keep naps short and avoid caffeine late in the day
If you feel tired during the day, you should be cautious about continuously drinking coffee or taking long naps. While this may temporarily reduce sleepiness, it can disrupt nighttime sleep, leading to a vicious cycle of feeling tired again the next day. If a nap is necessary, it is recommended to keep it short—around 20 minutes or less. If nap times become prolonged, it can delay your bedtime or disrupt your usual sleep rhythm. You must also look at the times you consume caffeine. The stimulating effects of caffeine can last for several hours, so drinking coffee or energy drinks in the late afternoon or evening can make it difficult to fall asleep at night. It is important to avoid the vicious cycle of consuming caffeine late into the night to reduce daytime fatigue, and then lacking nighttime sleep because of its effects, causing you to seek caffeine again the next day.
Check not only 'sleep duration' but also 'sleep quality'
If you continue to feel tired during the day even after getting enough sleep, you need to check whether it is due to simple sleep deprivation or other causes. If fatigue diminishes after supplementing the lack of sleep, it is likely the effect of sleep deprivation. Conversely, if fatigue persists despite adequate sleep and rest, it is hard to view it solely as a matter of sleep duration. At this time, what you need to check together is sleep quality. Even if your sleeping hours are sufficient, if you wake up frequently during the night or fail to get sound, restorative sleep, fatigue may linger in the morning. Therefore, maintaining consistent bed and wake times and checking your bedroom environment and lifestyle habits to see if there are any factors disturbing deep sleep will be helpful.
If fatigue persists even after changing lifestyle habits, underlying medical conditions should be checked If fatigue continues even after adjusting lifestyle habits, you need to check if there is an underlying causative condition. In particular, if you feel tired from the morning despite getting enough sleep, or if the fatigue is severe enough to hinder maintaining daily life during the day, it is difficult to dismiss it as simple sleep deprivation. One representative cause is obstructive sleep apnea. As breathing repeatedly becomes blocked during sleep, sleep is frequently interrupted, degrading sleep quality. Therefore, even if you think you slept enough, you can experience severe daytime sleepiness or fatigue. Insomnia and restless legs syndrome can also disturb nighttime sleep, leading to daytime fatigue. Aside from sleep disorders, there are various causes of fatigue. If you have anemia, your body's ability to supply oxygen to tissues drops, making you easily fatigued or lethargic. Thyroid dysfunction or certain autoimmune diseases can also be causes of continuous fatigue. Therefore, it is important to first observe whether fatigue improves with sufficient sleep and rest, and if symptoms recur or persist to the extent of interfering with work and daily life even after adjusting lifestyle habits, you should seek medical evaluation to determine the cause.
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