Taking any comfortable position and performing the asana, the yogi should draw in the air slowly, through the right nostril (Hatha Pradipika 2:48). Then he should be confined within, so that it fills from the nails to the tips of the hair, and then let out through the left nostril slowly (Hatha Pradipika 2:49). This excellent Surya Bhedana cleanses the forehead (frontal sinuses), destroys of Vata, and removes the worms and, therefore, it should be performed again and again (Hatha Pradipika 2:50).
Sit comfortably, close your eyes, close your left nostril with the mudra in your hand, inhale with the right nostril. The ratio can be 1:1:1 at the beginning and then 1:2:2 or 1:4:2 increasing gradually over a month. Then kumbhuka and then exhale slowly with the left nostril, this is one round. You can do 5-10 rounds in one sitting.
Marta Lucchini 