The recommended position while going to sleep is to sleep on the left side of the body, on the left hand, with the left nostril pressing against the pillow so as to keep the right nostril open.
The air currents passing through the left nostril control the right hemisphere of the brain and those passing through the right nostril control the left hemisphere of the brain. Each of these hemispheres in the brain control opposite and different kinds of qualities in a person. The left brain represents the male qualities of logic/reasoning and controls the fire element in the body. The right brain represents the female qualities of analogy/intuition and represents the water element in the body.
By closing the left nostril and breathing through the right nostril while retiring into bed, the left brain representing the fire element gets activated and this aids efficient digestion of food consumed during the day, leading to sound sleep and relaxation.
