Why did the old Chinese doctor say, "Never sleep with your feet facing west and east"?

The sleeping head should face south or north.

The earth is a big magnet, and its north pole and south pole are the positive and negative poles of the magnetic field. If people sleep in the direction of the north and south poles for a long time, that is, they sleep with their heads facing south or north, that is, they sleep along the magnetic lines of the earth's magnetic field, which can make the cells of human organs arrange orderly, adjust and improve organ functions, which is not only conducive to sleep, but also can make people energetic and eat.