Why is it told that we shouldn't sleep with our head pointing towards North?

The earth has got very powerful magnetic forces around it, that let’s it function the way it is. Iron is an important component in our blood stream and it’s required for our sustenance. Have you ever noticed that when you stand upright and when you keep your body horizontal, there is a difference in your blood pressure? This is because when the body is upright, the pressure needs to be high enough for the blood to traverse to various parts against gravity while in a horizontal direction a similar amount of pressure might actually damage or rupture the blood vessels. So the body adjusts. Similarly to gravity there is a magnetic field around earth as well and the body needs to be aligned in a direction which is in tandem with the magnetic field of earth.

Sleeping against the magnetic field of earth for a few days won’t cause any major harm but over a period it will affect. Know that there are small damages that do happen to your brain when pressure is exerted. Might not cause a major damage and cause you to go into a coma or die but slowly it affects your grey matter.

East – Best position to sleep.
West – Ok
South – Ok
North – No