There are 72000 nadis. These are broadly classified as Ida, Pingala and Sushumna. All the nadis are originating from the base of the spine. Ida and Pingala are running parallel to each other through spine. Ida is situated on the left side and pingala is on the right side of the spine. If we see architecture of spine there are two orifice on either side of the spine.
Ida and pingala are active in normal human body based on day and night cycle of the earth. Weakness, balance and over active of either of the Nadi will decide the various characteristics of individual( This will be discuss separately). But in short, Ida represents feminine nature comprising of lunar property and Pingala represents masculine nature comprising properties of sun.
However Sushumna is the centre nadi which remains dormant untill unless a certain amount of work is done over it. There are certain Yogic practices that helps to activate the kundalini power residing at the base of the spine. To know more about Sushumna here
