At present, due to the accelerated pace of life, many people feel that the time during the day is not enough, often use the night to do the work that is not done during the day, and even become a matter of habit. In addition, the colorful nightlife has emerged in the town, some late at night also soak in the ballroom, the concert hall, watch all-night movies or participate in other entertainment activities. As the city’s “late sleepers”, knowing that the dark circles under the eyes in the mirror have been unbearable, but also know that “men rely on food, women rely on sleep” the old adage, but overtime, parties, the Internet, watching discs, bars, pop… …The richer the nightlife is, the more reason we seem to have to indulge ourselves in withholding sleep and join the ranks of those who stay up late. Unbeknownst to us, staying up late greatly reduces sleep time, the brain and organs do not get rest and adjustment, bringing serious health hazards. Sleep is an important physiological process in metabolic activities. Without sleep, there is no health. Sleep deprivation not only does not replenish the body’s consumption, but also causes dysregulation of the internal environment due to insufficient hormone synthesis. Immunologists in the United States, after a series of studies on sleep and human immunity, concluded that sleep, in addition to eliminating fatigue, is also closely related to the ability to improve immunity and resist disease. People who have enough sleep have a significant increase in blood T-lymphocytes and B-lymphocytes, which are the main force of immunity in the human body. Sleepiness is a sign that the brain is quite tired and should not wait until then to go to bed. Only by developing the habit of going to bed regularly and ensuring that you get at least seven hours of sleep a day can you maintain the normal functioning of the biological clock of the sleep center. To sum up, normal sleep has a very important role in the regulation of nerves and endocrine and the repair of damaged cells. Therefore, we should learn to control our habits and not let our natural rhythm be disrupted and fall into a vicious cycle.