Among the 72,000 nadis in the human body, three are considered important, they are ida, pingala and sushumna nadis. They originate from the muladhara chakra. The ida and pingala nadis flows alternatively along the spinal column, while the sushumna nadi flows right through the middle of the spinal column. Ida and pingala are roughly translated as mind and body. The ida nadi is associated with the left nostril while the pingala nadi is associated with the right nostril. If the flow of breath in the left nostril is dominant it indicates ida is dominant, if the flow of breath in the right nostril is dominant it indicates pingala is dominant. When ida and pingala are balanced, the sushumna nadi becomes active and breath flows through both nostrils simultaneously. Sushumna nadi is the nadi which carries the kundalini energy to the sahasrara chakra. Though ida and pingala and their modes of activity are opposite, they are complimentary and must be balanced for total health and peace of mind. More than this though balance can open the door to the transcendental and to a new mode of functioning.
Ida is the energy within the personality which is passive, receptive, feminine, negative. At the physical level it is dark, cold, lunar, energy dissipating, disorganising, entropic, expansive and relaxing. This is the somopsychic aspect of man, where energy is inwardly directed, and the body acts on the mind. Ida controls the sense organs and therefore gives us knowledge and awareness of the world we live in.
Pingala can be defined as the dynamic, active, masculine, positive energy within our personality. It has a physical and mental side. Its material qualities are light, heat, solar, energy accumulating, creative, organizing, focused and contractive. Pingala is psychosomatic energy, outwardly directed, mind acting on body to motivate the organs of action, the karmendriyas. It is the basic energy of life.