Nāḍī (Sanskrit:नाड़ी,lit. 'tube, pipe, nerve, blood vessel, pulse') is a term for the channels through which, in traditional Indian medicine and spiritual theory, the energies such asprana of thephysical body, thesubtle body and thecausal body are said to flow. Within this philosophical framework, the nadis are said to connect at special points of intensity, thechakras.[1] All nadis are said to originate from one of two centres; the heart and thekanda, the latter being an egg-shaped bulb in thepelvic 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. Ultimately the goal is to unblock these nadis to bring liberation.
Nadi is an important concept inHindu philosophy, mentioned and described in the sources, some as much as 3,000 years old. The number of nadis of the human body is claimed to be up to hundreds of thousands and even millions. The three principal nadis areida,pingala, andsushumna.[2]Ida (इडा, iḍā "comfort") lies to the left of the spine, whereaspingala (पिङ्गल, piṅgala "orange", "tawny", "golden", "solar") is to the right side of the spine, mirroring the ida.Sushumna (Suṣumṇa "very gracious", "kind"[3]) runs along the spinal cord in the center, through the sevenchakras. TheShiva Samhita treatise onyoga states that, out of 350,000 nadis, 14 are particularly important, and among them, the three just mentioned are the three most vital.[1]
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 nadis play a role in yoga, as many yogic practices, includingshatkarmas,mudras andpranayama, are intended to open and unblock the nadis. When the channels are unblocked by the action of yoga, the energy ofkundalini uncoils and rises up thesushumna from the base of the spine.[2] The ultimate aim of some yogic practices is to direct prana into the sushumna nadi specifically, enablingkundalini to rise, and thus bring aboutmoksha, or liberation.[4]
"The nāḍis penetrate the body from the soles of the feet to the crown of the head. In them isprāṇa, the breath of life and in that life abidesĀtman, which is the abode ofShakti, creatrix of the animate and inanimate worlds." (VU 54/5)[6]
Several of the ancientUpanishads use the concept of nadis (channels). The nadi system is mentioned in theChandogya Upanishad (8~6 cc. BCE), verse 8.6.6.[7] and in verses 3.6–3.7 of thePrasna Upanishad (second half of the 1 millennium BCE). As stated in the last,
3.6 "In the heart verily isJivātma. Here, a hundred and onenāḍis arise. For each of these nāḍis, there are one hundrednāḍikās. For each of these, there are thousands more. In theseVyâna moves."
3.7 "Through one of these, theUdâna leads us upward by virtue of good deeds to the good worlds, by sin to the sinful worlds, by both to the worlds of men indeed." (PU Q3)[8][9]
The medievalSat-Cakra-Nirupana (1520s), one of the later and more fully developed classical texts on nadis and chakras, refers to these three main nadis by the names Sasi, Mihira, and Susumna.[10]
In the space outside the Meru, the right apart from the body placed on the left and the right, are the two nadis, Sasi and Mihira. The Nadi Susumna, whose substance is the threefold Gunas, is in the middle. She is the form of Moon, Sun, and Fire, even water also; Her body, a string of blooming Dhatura flowers, extends from the middle of the Kanda to the Head, and the Vajra inside Her extends, shining, from the Medhra to the Head.[11]
Inhatha yoga theory, nadis carryprana, life force energy. In thephysical body, the nadis are channels carrying air, water, nutrients, blood and other bodily fluids around and are similar to thearteries,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. energies (collectively described asprana) and are important for sensations, consciousness and the spiritualaura.[1]
Yoga texts disagree on the number of nadis in the human body. TheHatha Yoga Pradipika andGoraksha Samhita quote 72,000 nadis, each branching off into another 72,000 nadis, whereas theShiva Samhita states 350,000 nadis arise from the navel center,[1] and theKatha Upanishad (6.16) says that 101 channels radiate from the heart.[2]
The Ida and Pingala nadis are sometimes in modern readings interpreted as the two hemispheres of thebrain. Pingala is the extroverted (Active),solar nadi, and corresponds to the right side of the body and the left side of thebrain. Ida is the introverted,lunar nadi, and corresponds to the left side of the body and the right side of thebrain.[12]
Sushumna is the central and most important channel. It connects thebase chakra to thecrown chakra. It is important inYoga andTantra.[13][14] It corresponds to the river Saraswati.
Ida is associated with lunar energy. The wordida means "comfort" inSanskrit. Idā has a moonlike nature and feminine energy with a cooling effect.[15] It courses from the left testicle to the left nostril and corresponds to the Ganges river.
Pingala is associated with solar energy. The wordpingala means "orange" or "tawny" in Sanskrit. Pingala has a sunlike nature and masculine energy.[15] Its temperature is heating and courses from the right testicle to the right nostril. It corresponds to the riverYamuna.
The purpose ofyoga ismoksha, liberation and hence immortality in the state ofsamadhi, union, which is the meaning of "yoga" as described in thePatanjalayayogasastra.[16][17] This is obstructed by blockages in the nadis, which allow the vital air,prana, to languish in the Ida and Pingala channels. The unblocking of the channels is therefore a vital function of yoga.[17] The various practices of yoga, including the preliminary purifications orsatkarmas, the yogic seals ormudras, visualisation, breath restraint orpranayama, and the repetition of mantras work together to force the prana to move from the Ida and Pingala into the central Sushumna channel.[17] The mudras in particular close off various openings, thus trapping prana and directing it towards the Sushumna. This allowskundalini to rise up the Sushumna channel, leading to liberation.[17][18][19]
Other cultures work with concepts similar to nadis and prana.
Systems based onTraditional Chinese Medicine work with an energy concept calledqi, analogous toprana.[20] Qi travels throughmeridians analogous to the nadis. Themicrocosmic orbit practice has many similarities to certain Indian nadi shuddha (channel clearing) exercises and the practice ofKriya Yoga.
Tibetan medicine borrows many concepts from Yoga through the influence ofTantric Buddhism. One of theSix Yogas of Naropa is a cleansing of the central channel calledphowa, enabling the transfer of consciousness to apure land through thesagittal suture.[21]
The Vajrayana practice ofTrul Khor is another practice used to direct and control the flow of energy within the body's energetic meridians through breath control and physical postures.[22]
The three main nadis have been compared to theCaduceus 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".[23]
