Within the spine, there are two holes on either side of the spine which are like conduit pipes for all the nerves to pass. This is the Ida and the Pingala, the left and the right channels.The ida (comfort) and pingala (tawny) nadis spiral around the sushumna nadi like the double helix of our DNA, crossing each other at every chakra.
Prana energy moves in the body through 72,000 nadis, just like current. The 72,000 ways spring from three basic ways – the Ida, Pingala, and Sushumna. The word “nadi” does not mean nerve. Nadis are pathways of prana in the body. Threse 3 basic nadis are of particular interest to yogis. The sushumna nadi is the main gate running from the base of the spine to the crown of the head, passing through each of the seven chakras in its course. It is the channel through which energy and the higher spiritual consciousness rises up from its origin at the root chakra to its true home at the sahasrara chakra at the crown of the head. The sushumna nadi is the path to enlightenment.
The ida nadi begins and ends on the left side of sushumna. Ida is cool and nurturing by nature, and is said to control all mental processes and the more feminine aspects of our personality. Pingala, begins and ends to the right of sushumna. It is warm and stimulating by nature, controls all vital somatic processes, and oversees the more masculine aspects of our personality. The interaction between ida and pingala corresponds to the internal dance between intuition and rationality, consciousness and vital power, and the right and left brain hemispheres. In everyday life, one of these nadis is always dominant. Although this dominance alternates throughout the day, one nadi tends to be ascendant more often and for longer periods than the other.
Yogis move Prana energy through spine, guiding its circulatory movement through Sushmana and then awaken and energizing the seven chakras. Once the Kundalini Shakti has ascended through Sushumna to Sahasrara, the highest psychic center at the crown of the head, it is made to reverse its course and return to rest in the base center again.
One must not try these serious meditations on their own. An experienced person must teach these techniques properly.