It is best to choose the bed with north-south orientation, smoothness and geomagnetic attraction. Sleeping with your head facing south or north is good for your health, because the aorta and great veins are the most important in the human blood circulation system, and their directions are consistent with the direction of your head and feet. When the human body is in the north-south sleeping position, the directions of aorta and great vein, the sleeping position of the human body and the north-south magnetic field lines of the earth are the same. At this time, people are the easiest to fall asleep and the quality of sleep is the highest, so the north-south sleeping direction 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, the blood tends to go straight to the top of the head and sleep is unstable. If you sleep with your head facing east, you will feel a sense of peace.