The three principal nadis are the sushumna, ida and pingala. While the sushumna is the central channel, the ida (left) and pingala (right) nadis start and end on opposite sides of sushumna. Once the vitality of the pingala nadi and creativity of the ida nadi are in balance, prana is free to travel along the sushumna nadi, from the root chakra to the crown chakra.
As the prana travels up the sushumna nadi, it energizes all of the chakras along the way and stimulates dormant segments of the mind that are responsible for higher thought and feeling. Sushumna is, therefore, known as the pathway to salvation or enlightenment.
A major focus of Hatha yoga is balancing the nadis to allow the free flow of the life-force energy. The principal ways of balancing the nadis in yoga practice are through pranayama (breathing exercises) and meditation. For example, nadi shodhana pranayama, or "alternate nostril breathing," is believed to balance the ida and pingala nadis, thereby opening the energy paths of the sushumna nadi.