The trend of sleep is influenced by four seasons, environment, wind direction, indoor sunshine and other factors, which is closely related to people's health. China ancient health experts put forward the following sleeping directions according to the theory of the correspondence between man and nature and the generation of five elements. 1. Lying in the east-west direction: The article "A thousand dollars must be decided, and the forest should cultivate nature" says: "Ordinary people lie, facing east in spring and summer, and facing west in autumn and winter." Lao Heng Yan quoted Bao Sheng Xin Jian and also advocated: "The place to lie is in the east of spring and summer, and in the west of autumn and winter." Think that spring and summer belong to the sun, and your head should lie east; It is cloudy in autumn and winter, and the head should lie to the west, which conforms to the principle of "nourishing yang in spring and summer and nourishing yin in autumn and winter". 2. lie facing east: some health workers advocate lying facing east all year round and not changing at four o'clock. For example, Lao Lao Heng Yan quoted a sentence from China's Yu Ji Zao: "Sleeping in the East is the first time, which means sleeping on the salary." The head is the meeting of all yang on the top of the human body, and it is the place where qi and blood rise and rise, while the East Earthquake is the main spring, which can rise and rise the qi of all things, so lying with the head facing east can ensure that the mind is clear and clear. 3. Determine the decubitus direction according to seasons: Some health experts believe that the decubitus direction should be determined according to different seasons, that is, east in spring, south in summer, west in autumn and north in winter, so as to cope with the four seasons and coordinate qi, blood, yin and yang. 4. Don't lie with your head facing north: "Qian Jin Fang Yao Dao Lin Nourishes Nature" puts forward: "Don't lie with your head facing north, and don't sleep in the north of the wall." Old Heng Yan also said: "Don't lie in the north first, which means avoiding Yin Qi." Ancient health experts basically agreed with this point, thinking that the north belongs to the shade of water and yin, and lying in the cold is afraid that the north will hurt the human yang and the house of the Yuan God. Clinical investigation shows that the incidence of cerebral thrombosis in the elderly lying with head north and feet south is higher than that in other lying positions. Foreign data also show that lying with head north and feet south is easy to induce myocardial infarction.