Nadi (yoga)

[1] All nadis are said to originate from one of two centres; the heart and the kanda, the latter being an egg-shaped bulb in the pelvic area, just below the navel.

[1] The three principal nadis run from the base of the spine to the head, and are the ida on the left, the sushumna in the centre, and the pingala on the right.

Sushumna (Suṣumṇa "very gracious", "kind"[3]) runs along the spinal cord in the center, through the seven chakras.

When the channels are unblocked by the action of yoga, the energy of kundalini uncoils and rises up the sushumna from the base of the spine.

[2] While the sushumna came to be envisioned as a vertical channel extending upwards from the heart, navel region, or base of the torso, there is an old precedent for the idea that it extends, like the śaktitantu, to the feet: the Mataṅgapārameśvara, a comparatively early Siddhāntatantra, envisions the sushumna running from the tips of the big toes to the crown of the head via the navel and heart.

This archaic model of a central channel extending to the feet, linking together the principal series of nine lotuses [i.e., Kapālīśabhairava, the four Devīs and the four Dūtīs] spanning the body’s axis from crest (śikhā) to feet (pāda), may underlie the Brahmayāmala’s conception of the śaktitantu.

The ultimate aim of some yogic practices are to direct prana into the sushumna nadi specifically, enabling kundalini to rise, and thus bring about moksha, or liberation.

In the physical body, the nadis are channels carrying air, water, nutrients, blood and other bodily fluids around and are similar to the arteries, veins, capillaries, bronchioles, nerves, lymph canals and so on.

[1] In the subtle and the causal body, the nadis are channels for so-called cosmic, vital, seminal, mental, intellectual, etc.

[16][17] This is obstructed by blockages in the nadis, which allow the vital air, prana, to languish in the Ida and Pingala channels.

[17] The various practices of yoga, including the preliminary purifications or satkarmas, the yogic seals or mudras, visualisation, breath restraint or pranayama, and the repetition of mantras work together to force the prana to move from the Ida and Pingala into the central Sushumna channel.

Systems based on Traditional Chinese Medicine work with an energy concept called qi, analogous to prana.

One of the Six Yogas of Naropa is a cleansing of the central channel called phowa, enabling the transfer of consciousness to a pure land through the sagittal suture.

[22] Sometimes the three main nadis are related to the Caduceus of Hermes: "the two snakes of which symbolize the kundalini or serpent-fire which is presently to be set in motion along those channels, while the wings typify the power of conscious flight through higher planes which the development of that fire confers".

A simplified view of the subtle body of Indian philosophy , showing the three major nadis or channels, the Ida (B), Sushumna (C), and Pingala (D), which run vertically in the body
The Varaha Upanishad (13–16 cc. CE) further describes it as follows: [ 5 ]

"The nāḍis penetrate the body from the soles of the feet to the crown of the head. In them is prāṇa , the breath of life and in that life abides Ātman , which is the abode of Shakti , creatrix of the animate and inanimate worlds." (VU 54/5) [ 6 ]

The practices of yoga work together to force prana into the central Sushumna channel, allowing kundalini to rise, leading to moksha , liberation. The shatkarmas purify the nadis, while the mudras trap prana, and other practices (not shown) force the prana out of the Ida and Pingala channels. [ 4 ]
Manuscript painting of a yogin in meditation, showing the chakras and the three main channels (nadis) of the subtle body. A small serpent, symbolising the Kundalini , climbs up the central sushumna channel; she will pierce each chakra as she climbs. When she reaches the head she will unite with Shiva; the yogin will then be liberated in his body.