2. It is best to choose the north-south orientation for the bed. In the blood circulation system of human body, aorta and great vein are very important, and their directions are consistent with the head and feet of human body. When people sleep in the north-south direction, the direction of aorta and great vein is consistent with the direction of magnetic field lines in the north-south direction of the earth, which makes people fall asleep most easily and has the highest sleep quality, so the north-south sleep phase has certain disease prevention and health care functions. The bedside should not face west, because the earth rotates from east to west. If the head is facing west, blood often rushes out from the top of the head, and sleep is unstable. If you sleep with your head facing east, it will give you a stable sleep.