Each of us has a natural sleep-wake cycle. This is the pattern of sleeping and being awake which we follow every day. We do not think about this cycle because for most of us sleep comes naturally. However, many people have trouble sleeping and are unable to get the rest they need. Over a period of time, this condition can cause problems.
A person’s sleep-wake cycle is a complex process that scientists have not fully understood. What is known, however, is that it is greatly influenced by a hormone called melatonin.
Produced by the pea-size pineal gland in the brain, melatonin helps the body to regulate its sleep-wake cycle. A high level of melatonin tells the body that it is time to sleep, and a low level tells the body that it is time to wake up.
The pineal gland is normally inactive during the day. However, when the sun goes down and darkness comes, it ‘switches on’ and begins producing melatonin. As a result, the melatonin level in the blood rises sharply and you become less alert and feel sleepy. The melatonin level remains high throughout the night. When daylight comes, the pineal gland stops production and the level decreases. You become more alert and less sleepy.
Certain situations can disrupt melatonin production. One example is when you fly through different time zones. It may be daytime where you are so your body stops producing melatonin. However, because it is nighttime back home and you should be asleep, your body should really continue to make the hormone. Thus, your body feels tired but your mind is still alert and you are unable to fall asleep. This condition is called jet lag. Other causes of disruption include night shifts, rotating shifts and stress. Frequent disruptions in melatonin production may impair the ability to think clearly and make sound decisions.
Melatonin production differs from person to person. It also varies according to age and sex. Children and teenagers tend to produce large amounts of the hormone, while older adults produce relatively little. This may explain why many older adults have insomnia.Sponsored links: