Respiration is the third component of human existence. It affects everyone. There is a mention of delhi deepak nyaya in Nyaya Shastra (Jurisprudence). It means that the lamp kept on the doorsill throws its light in the interior as well as on the exterior. The breath affects the body and the senses both. It also affects the mind and the emotions. The breath is the main factor that affects everything.
Just as there is a chakra (wheel) of the segments of the brain, there is also a chakra of the breath. On the basis of deep study in the field of functioning of the brain it has been said that there is a chakra governing the functioning of the right and the left segments of the brain. The direction of that functioning is fixed. One segment of the brain remains active for ninety minutes, after which the other segment becomes active.
The same is true with regard to the breath. Sometimes the right side breathing and sometimes the left side breathing remains active. The breath too has its regular recurrence, a cycle which moves continuously. When there is breathing on the left side, the right segment of the brain becomes active. When there is breathing on the right, the left segment of the brain becomes active. From the point of view of health, it is necessary to understand these rules about respiration. Lot of work in yoga has been done in regard to health. Plenty of work has been done in svarodaya also. Respiration has so many processes and so many peculiarities that if they are properly understood, innumerable problems concerning health can be answered.