Sleep is not just a rest, but an essential factor that determines health and quality of life. This article discusses the role and importance of sleep and how to get quality sleep.
Sleep refers to the state of regular sleep to recover the body and mind from accumulated fatigue. Because sleep is essential for the recovery of the body and mind and for the maintenance of life, Shakespeare called sleep “nature’s gentle nurse. Sleep alternates between “non-REM sleep” and “REM (rapid eye movement) sleep,” which is characterized by rapid eye movement. Generally, non-REM sleep is followed by REM sleep. Non-REM sleep is a four-stage sleep that leads to deep sleep. The characteristics of this type of sleep can be observed in brain waves, which are measured differently depending on the stage of sleep.
The importance of sleep goes beyond physical and mental recovery. According to various studies, sleep also plays an important role in the formation of memory and the regulation of emotions. Not getting enough sleep can lead to poor concentration, emotional swings, and even negative long-term health effects. In particular, chronic sleep deprivation has been linked to several health problems, including cardiovascular disease, obesity, and diabetes. Therefore, improving sleep quality is very important for improving overall quality of life.
First, in the first stage of sleep, just as you begin to fall asleep, the brain emits “theta waves”. Theta waves are brain waves that occur during light sleep, and in this stage you are in a state of sleep that is close to being able to wake up at any time. This stage is a transitional state from wakefulness to sleep, and the brain waves gradually slow down from wakefulness.
In the second stage of sleep, unique brain waves called “sleep spindles” and “K-complexes” appear between theta waves. Sleep spindles are dense waves that look like a thread wrapped around the middle of theta waves, appearing about 2 to 5 times per minute, and play a role in maintaining sleep. The K-complex appears in the second stage of sleep and shows a sudden spike in theta waves. Experiments have shown that the K-complex is activated when there is a sudden noise during sleep. This suggests that it plays a role in preventing the sleeper from being awakened, thereby inducing deep sleep.
As we move into the deep sleep stage, the slowest and most amplitude-rich “delta waves” appear among the brain waves. The third and fourth stages are distinguished by the proportion of delta waves. Usually, when the proportion of delta waves is between 20 and 50%, it is considered to be in stage 3, and when it falls deeper into sleep beyond 50%, it is considered to be in stage 4. Therefore, stage 4 sleep is also known as “slow-wave sleep.
Slow-wave sleep is a state of deep sleep in which the brain’s metabolic rate and blood flow are reduced to 75% of what they are during wakefulness, while REM sleep is a state in which mental activity occurs even though the person is asleep. Therefore, if a person in slow-wave sleep is awakened, he or she will be confused, groggy, and disoriented, while a person in REM sleep will quickly return to an alert state when awakened.
Non-REM sleep, in which the body does not respond to stimuli, brings true physical and mental recovery through complete rest. REM sleep, where mental activity occurs during sleep, also helps the human brain function and learn. Problems with either non-REM or REM sleep will affect human activity.
Therefore, it is important to maintain healthy sleep habits. Regular sleep schedules, a comfortable sleep environment, adequate exercise, and controlling caffeine intake are essential for quality sleep. In addition, it is important to reduce the use of electronic devices such as smartphones and computers in modern society. This is because the blue light emitted by electronic devices can disrupt sleep by suppressing the secretion of melatonin, a sleep hormone.
To improve sleep quality, it is also important to find a sleep routine that fits your personal lifestyle. It is desirable to find a sleep time that matches your biological rhythm and maintain it consistently. For example, morning people and night owls have different sleep patterns, so it is better to adapt to your own body rhythm.
Overall, we should not forget that sleep is not just a process of ending the day and starting a new one, but an important factor that affects our overall health and quality of life. We should recharge our body and mind with sufficient and quality sleep so that we can face a better day.
