One third of each person’s life is spent in sleep. Some studies have shown that a normal person will die after five days without sleep, which shows the importance of sleep. Sleep, as a process necessary for life, is an important part of the body’s recovery, integration and consolidation of memory, and is an indispensable component of health. According to the World Health Organization survey, 27% of people have sleep problems. The Global Sleep and Health Program, sponsored by the International Organization for Mental Health, launched a global campaign in 2001 to designate March 21, the first day of spring, as “World Sleep Day”. This is a reminder that people should pay attention to sleep and that it is important to arrange sleep scientifically according to the physiological characteristics of people. Sleep time 9-11pm: It is the time for the immune system (lymph) to detoxify, so you should be quiet or listen to music during this time. 11pm-1am: Detoxification of the liver, which needs to be done in a sound sleep. 1-3 a.m.: Detoxification of the bile, which also needs to be done in a sound sleep. 3-5 a.m.: Detoxification of the lungs. This is why people with coughs cough most intensely during this time, because the detoxification action has gone to the lungs; cough medicine should not be used, so as not to inhibit the elimination of waste products. 5-7 a.m.: Detoxification of the large intestine, you should go to the toilet to defecate. 7-9 a.m.: the small intestine to absorb a lot of nutrients time, should eat breakfast. It is best to eat early, before 6:30 a.m. for those who heal, before 7:30 a.m. for those who maintain their health, and those who do not eat breakfast should change their habits, even if they delay eating until 9 or 10 a.m. is better than not eating. Midnight to 4:00 a.m. is the time of spinal blood production, you must sleep well, should not stay up late. According to the recommendations of sleep experts, in order to have a good sleep, in the environment need to pay attention to do the following: 1, a reasonable arrangement of sleep time. 2.Arrange the bedroom well. 3, sleep should be in a safe, comfortable, quiet and relaxing place. 4, carefully select the bed and bedding, because a third of your life will spend with them. The bed is too soft or too hard can cause back pain. Bedding should also be kept comfortable. 5.Avoid outside disturbances (light and noise). 6, keep the air and humidity in the bedroom, if necessary, you can put a wet towel on the heater or install a humidifier. 7.The temperature of the bedroom should be maintained at 16℃ to 18℃.