Sleep is a vital activity for the body. Although we once thought that it was just a time to relax, scientists now realize that sleep is a time for the brain to process information, improve its health, and restore its energy levels. Despite the many benefits of sleep, many people still don’t get enough of it.
In experimental studies, sleep has been defined in terms of physiological variables, which occur during periods of inactivity. These physiological variables include electroencephalogram (EEG) patterns. An absence of EEG patterns is believed to be indicative of absence of sleep. However, this method is not always very accurate at identifying sleep and wakefulness.
The typical adult sleep pattern is characterized by the onset of NREM sleep, emergence of substages of NREM sleep, and a decline in slow-wave activity. An average night’s sleep has 70 to 90 minutes of NREM sleep. The first stage of REM sleep lasts five to fifteen minutes.
The human body also produces cytokines, which help fight inflammation and infection. These proteins produce immune cells and antibodies, which help our bodies fight disease and stay healthy. However, not getting enough sleep may cause health problems. Sleep is also essential for emotional health. It increases activity in areas of the brain that control emotions, such as the amygdala. A healthy body needs at least 7 hours of sleep per night to function properly.
People can take steps to improve their sleep habits. First, they can try to get more sleep by limiting the number of screens they use in the bedroom. This can improve the quality of their sleep and their mood in the mornings. They should also avoid napping after three p.m., and stay away from electronic devices before bed.
Insufficient sleep disrupts the body’s hormone-making system, which is crucial for a healthy weight. The lack of sleep also lowers the levels of hunger hormones ghrelin and leptin, which control appetite and make us feel full after eating. However, these hormone levels fluctuate during sleep, meaning sleep deprivation can result in weight gain.
The average adult should get eight hours of sleep per night, while adolescents and toddlers require around nine to twelve hours. Children under five should get at least seven hours. For children younger than five, this amount may be more than doubled. If not, they may experience grogginess and lack the ability to concentrate, follow directions, and even perform well in sports.
The first three stages of sleep are composed of non-REM activity. This stage is known as “light sleep” and is often characterized by a lower heart rate and slow-pace breathing. During the third and fourth stages, the body slows down and its temperature drops. Once these changes are complete, the brain enters a deep sleep phase.
A healthy adult should sleep seven to nine hours per night. However, increasing numbers are sleeping less than that and fewer than eight hours. In the United States, sleep polls show that the average number of people sleeping less than seven hours a night increased from 1998 to 2009, and the number of people sleeping longer than eight hours a night decreased from 35 percent to 28 percent. Sleep time also varies between weekdays and weekends.