One Korean television shows, Wow How, once aired a story about a university student who stopped sleeping. While everybody else was asleep, he went to the library alone to study. This story shocked many viewers because sleeping is considered as a necessary activity for human beings.
On the other hand, in the movie One Step More to the Sea, a female high school student suffers from narcolepsy, which is a disorder where a person sleeps too much regardless of time and space. In the movie, she falls asleep in the middle of her walking.
When the sun sets and night comes, people prepare to go to bed. It is normal for humans to sleep about seven to eight hours each day. People feel heavy eyelids and become unable to focus on things when they are sleepy. Then, why do humans have to sleep? And if sleep is necessary for human beings, how can people sleep efficiently?
Why Do Humans Sleep?
Doctor Han Jin-kyu, the Head of the Seoul Sleep Center, said, "People go to sleep when the body temperature goes down. Also, the effect of hormones is related to sleeping. The hormone called melatonin is a dark hormone which is produced only during night time. When the body temperature goes down and that moment is identical with the cycle of the bio-clock, people fall asleep. Then the brain wave detector senses the brain waves related to sleep. The bio-clock has a 24.3 hour cycle. Since there is a difference between real time and the bio-clock, body temperature plays the role to offset the difference." There is a bio-clock in every cell of the human body. This bio-clock is what orders the body to go to bed. For the past 20 years, many biologists have tried to explain the regular cycle of how humans can fall asleep without being exposed to sunlight, which is the operation of the bio-clock. According to research reported in the science magazine Discovery done by researchers at Dartmouth University, Harvard University, and San Diego Scripps Research Institute, the nucleus of each human cell conveys the bio-clock which works similarly as the water-clock.
The water-clock is operated by constant water drops. When the water is full in the waterspout, gathered water is poured out and the new cycle of the water-clock begins. This cycle is repeated regularly and the bio-clock works similarly.
The bio-clock's cycle starts in the nucleus of the cell. In the nucleus, there is a gene which causes the operation of the bio-clock. This gene sends a signal to the DNA which then creates the clock-protein which plays the role of water drops for the water-clock. As time goes by, the clock-protein is accumulated in the cell. When the protein is accumulated, it creates a specific structure and enters the nucleus. When the nucleus is filled with clock-protein, it orders the DNA to stop sending protein to decrease the amount. Then, a new cycle begins.
As the case of the student who does not sleep or the character in the movie that sleeps too much show, there are various disorders related to sleep. The purpose of sleeping is to give time for the heart and brain to rest. "Only while a human sleeps, the immune and growth hormones are emitted. That is why children should sleep enough. I recommend to sleep seven and a half hours each day. In the case of children, they should sleep more than nine hours to produce enough hormones," said Doctor Han. Therefore when people do not sleep well, it will affect how the brain and heart work.
Han added, "Not sleeping enough can be a problem. But, sleeping too much is also harmful for our health." According to a Japanese Collaborative Cohort Study, when a human sleeps less than five hours or over nine hours, he or she has higher chance to die early. Also, Archives of General Psychiatry, a medical magazine, reported that people who sleep less than five hours or over nine hours have a high possibility of suffering from cancer.
The result of a survey held by the Sleep Epidemiology Center of Saint Vincent? Hospital showed that 12 percent of participants replied that they have experienced insomnia more than three times a week. Lee Seung-jin, a student of the Department of English Language and Literature said, "I once suffered from insomnia. I kept saying to myself that I should stop thinking of meaningless stuff. I also tried to make myself as tired as possible. When I still could not fall asleep, I took sleeping pills."
However, insomnia is curable. The reason for insomnia is the disharmony of the bio-clock and low body temperature. When the disharmony continues, it causes severe insomnia for humans. With care by experts and proper sleeping habits, insomnia can be cured. Doctor Han said, "When people cannot fall asleep, they usually start counting sheep. But that will only awake their brain by causing high body temperature and preventing them from falling asleep." On the other hand, narcolepsy is a hereditary disease and it cannot be cured. Even though there is medicine to help people with narcolepsy to maintain normal life, once the patient stops taking medicine, they will go back to excessive sleep. Without the medication, they will not be able to have a regular social life or receive a proper education. "The only side-effect of narcolepsy is that sufferers sleep too much when they are in adolescence which is the time people need to study and make social interactions. Narcolepsy is cured naturally as a human gets old. But when they get old and look back at their lives, they would only remember sleeping," Han explained.
"Another disorder is restless leg syndrome. Restless leg syndrome is found mostly in female patients and 15 percent of Koreans are suffering from the disease. Because of improper sleep, the brain creates less dopanine than needed. When people do not fall asleep deeply, it affects the body and especially the legs. The symptoms of restless leg syndrome are swollen legs, sleeping with rolled bedsheets between legs, or needing sleeping socks," explained Doctor Han.
Among various sleeping disorders, snoring is the most dangerous of all. Doctor Han explained, "Only the breath through nose goes to the brain. Breathing through mouth does not supply oxygen to the brain causing high blood pressure. Other than high blood pressure, snoring can cause other deadly diseases or sudden heart attack. Snoring sound is an indicator of the lung pumping to provide oxygen to the brain. But people are not aware of how important it is to cure it."
To have a good sleep, the sunlight is very important. When one is exposed to a sufficient amount of the sunlight for 30 minutes every morning, melatonin is made from the body after 15 hours. While exposing oneself to the sunlight, exercising is not recommended. Reading a newspaper or taking a walk will be fine. Also, at the workplace, it is recommended to try to see as much light as possible.
If one wants to exercise in the afternoon, it must be at least three hours before he or she goes to bed. Exercising makes body temperature go up which eventully awakes the body. To go to sleep, both body and mind must be relaxed.
Environment is another key to sleep well. Making the environment darker helps produce melatonin. Taking a warm bath two to three hours before going to bed also helps to have a good sleep. Because a bath momentarily makes body temperature high, it will naturally lead the body temperature to a lower level to sleep well.
Finally, if one strives to fall asleep, such efforts will only make sleep run away. Worrying will only result in high body temperature. Sleeping is a natural process of the human body. When people focus on what they do during the day time and enjoy it, sleep will naturally come at night. Therefore, preparing to sleep from the beginning to the end of the day leads to good sleep by creating enough melatonin and helps humans have a good-night sleep.
To examine whether one is having a good sleep or not, Doctor Han explained, "If people take a look at their sleep postures, they can tell if they are sleeping well or not. Sleeping straight facing the ceiling is the best posture. Also, if one feels refreshed and has moist lips when they wake up, it means they have slept okay."
Caring About Sleep
Human beings spend almost one-third of their life sleeping. Only by sleeping, humans can gain energy and live a healthy life. Doctor Han said, "Sleeping is related to so many fields of medicine, such as, neurology, dentistry, internal disease, and so on. Also, the age range of people who suffer from sleep diseases varies from two-year-old babies to elders. However, a long time ago when people lived by following the cycle of nature, there were less sleep disorders than today. After Edison invented the light bulb, people became able to work even at night. Then, the rate of sleep diseases started to increase." Even though the sleep diseases are increasing in numbers, people do not realize the importance of sleep or try to cure the problems related to sleep. To live a better and a healthier life, people should recognize and care about their sleep and have a good night? sleep.