Sleeping directions according to Vastu are guidelines to sleep in a way so that you receive favorable energies and reject unfavorable ones. Each direction has its own effect on the person sleeping. But, as per vastu, you are free to sleep with your head in any direction EXCEPT NORTH.
It is the responsibility of every architects and builders to take this into construction while constructing a house, and make sure all bedrooms are designed so as to accommodate the right Vastu for the welfare of the occupants.
Why? Because...
North
To sleep with your head facing North, is strongly opposed. It might cause major illnesses and sleepless nights for the person sleeping in such a position.
South
Vastu Shastra highly recommends sleeping facing towards South, as this is believed to provide sound sleep and increase the wealth and prosperity in the household.
East
Keeping your head in East direction increases memory, concentration and good health. Students must sleep with their head facing East in order to increase their memory, grasping power and concentration.
West
Sleeping in west is also a favourable direction. Sleeping with your head facing West gives you fame, reputation and prosperity.