नाडीnāḍī · channel, tube
The nāḍīs, ida, pingala and sushumna
3 min read · Updated October 16, 2026 · sources checked October 16, 2026
In short
Nāḍīs are the channels of the subtle body through which prāṇa flows. The texts count 72,000 of them, name ten main ones, and give three the central role: iḍā on the left, linked to the moon; piṅgalā on the right, linked to the sun; and suṣumnā in the middle, the path of Kuṇḍalinī. Pranayama aims to purify them so the breath enters suṣumnā.
नाडी (nāḍī) means a tube, a pipe, a hollow stalk. In medical texts it can mean a vessel; in yoga it names the channels of the subtle body through which prāṇa moves. The idea is far older than haṭha yoga: the Upanishads already speak of channels from the heart.
In the Upanishads: 72,000 and 101
The famous figure of 72,000 channels comes from the Bṛhadāraṇyaka Upaniṣad. In deep sleep, it says, the self withdraws through them:
हिता नाम नाड्यो द्वासप्ततिः सहस्राणि हृदयात्पुरीततमभिप्रतिष्ठन्ते
hitā nāma nāḍyo dvāsaptatiḥ sahasrāṇi hṛdayāt purītatam abhipratiṣṭhante
There are channels called hitā, seventy-two thousand, which extend from the heart to the pericardium.
Elsewhere (4.3.20) the same Upaniṣad says these hitā channels are as fine as a hair split a thousand times, filled with white, blue, tawny, green and red.
The Kaṭha Upaniṣad gives another image, which yoga will inherit:
शतं चैका च हृदयस्य नाड्यस्तासां मूर्धानमभिनिःसृतैका । तयोर्ध्वमायन्नमृतत्वमेति
śataṃ caikā ca hṛdayasya nāḍyas tāsāṃ mūrdhānam abhiniḥsṛtaikā | tayordhvam āyann amṛtatvam eti
The channels of the heart are a hundred and one; one of them goes out towards the crown of the head. Rising through it, one reaches the deathless.
That single channel rising to the crown is what later yoga calls suṣumnā.
In the haṭha texts: ten, then three
The Gorakṣaśataka, a Nātha text, names ten main channels and their "doors" (verses 18-22):
| Nāḍī | Opening in the Gorakṣaśataka |
|---|---|
| iḍā | the left side |
| piṅgalā | the right side |
| suṣumnā | the middle |
| gāndhārī | the left eye |
| hastijihvā | the right eye |
| pūṣā | the right ear |
| yaśasvinī | the left ear |
| alambuṣā | the mouth |
| kuhū | the region of the genitals |
| śaṅkhinī | the root (base) |
The Śiva Saṃhitā (2.13-2.15 in Vasu's translation) raises the total to 350,000, names fourteen principal channels, and says that among them iḍā, piṅgalā and suṣumnā are chief, and suṣumnā alone the highest (2.16). The Haṭhapradīpikā (4.18, GRETIL numbering) keeps 72,000 openings in the "cage" of the body, and adds that suṣumnā alone matters; "the others are of no use".
Iḍā, piṅgalā, suṣumnā
| iḍā इडा | piṅgalā पिङ्गला | suṣumnā सुषुम्ना | |
|---|---|---|---|
| Side | left | right | centre |
| Associated with | the moon, coolness | the sun, heat | fire; the path of Kuṇḍalinī |
| River (Haṭhapradīpikā 3.110) | Gaṅgā | Yamunā | (between them) |
The Haṭhapradīpikā gives them sacred geography:
इडा भगवती गङ्गा पिङ्गला यमुना नदी । इडापिङ्गलयोर्मध्ये बालरण्डा च कुण्डली ॥
iḍā bhagavatī gaṅgā piṅgalā yamunā nadī | iḍā-piṅgalayor madhye bālaraṇḍā ca kuṇḍalī ||
Iḍā is the holy Gaṅgā, piṅgalā the river Yamunā; between iḍā and piṅgalā is the young widow, Kuṇḍalī.
The confluence of the Ganga and the Yamuna at Prayāga is one of the holiest places in India; the text places it inside the body. The Śiva Saṃhitā does the same with Vārāṇasī: iḍā and piṅgalā are the rivers Varaṇā and Asī, and the space between them is Vārāṇasī, the city of Śiva (5.100 in Vasu's translation).
The same text names suṣumnā many ways (3.4): the void path, brahma-randhra, the great way, the cremation ground, śāmbhavī, the middle path. The Ṣaṭ-cakra-nirūpaṇa (verses 1-2, Avalon 1919) adds three channels nested inside suṣumnā: vajrā, citriṇī "subtle as a spider's thread", and the innermost brahma-nāḍī, on which the chakras are strung like lotuses on a stem.
Good to know
Texts disagree on the details. The Śiva Saṃhitā (2.25-2.26, Vasu) has iḍā coil round suṣumnā and end at the right nostril, piṅgalā at the left; most later teaching links iḍā with the left nostril. Read each text on its own terms rather than forcing one system.
Purifying the channels
For the haṭha texts, the channels are obstructed by impurities (mala), and while they are, the breath cannot enter the middle channel (Haṭhapradīpikā 2.4). The remedy is prāṇāyāma practised daily with a calm (sāttvika) mind, so that the impurities in suṣumnā are cleared (2.5-2.6). The first technique taught is nāḍī-śodhana, "purification of the channels": alternate nostril breathing, described in the next verses (2.7-2.10). The aim of much of haṭha yoga, including the locks (bandha) and seals (mudrā), is to make prāṇa leave iḍā and piṅgalā and enter suṣumnā, where Kuṇḍalinī rises.
Nāḍīs and modern anatomy
The nāḍīs are not visible in anatomy, and no Sanskrit text claims they are. In the early twentieth century, some authors compared iḍā and piṅgalā to the left and right sympathetic nerve chains and suṣumnā to the spinal cord; the foreword of Vasu's 1914-1915 edition of the Śiva Saṃhitā already does so. These are modern comparisons. The texts describe channels to be felt and visualised in practice, part of a map of the subtle body that also includes the five vāyus and the chakras.
Questions people ask
How many nadis are there?
The Bṛhadāraṇyaka Upaniṣad, the Gorakṣaśataka and the Haṭhapradīpikā give 72,000; the Śiva Saṃhitā gives 350,000. The figures express an immense network rather than a count.
Which nadi is on the left side?
Iḍā, associated with the moon, is on the left; piṅgalā, associated with the sun, on the right; suṣumnā runs in the middle. Texts differ on their exact course to the nostrils.
Are nadis the same as nerves?
No. The texts describe channels of prāṇa to be felt and visualised in practice. Some modern authors compared them with nerves; that comparison is modern and not found in the Sanskrit texts.
How do you purify the nadis?
The Haṭhapradīpikā teaches prāṇāyāma, above all alternate nostril breathing, practised regularly and without force (2.5-2.10).
Sources
- Bṛhadāraṇyaka Upaniṣad (Kāṇva recension) 2.1.19 and 4.3.20, Sanskrit text (GRETIL) checked October 16, 2026
- Kaṭha Upaniṣad 6.16, Sanskrit text (GRETIL) checked October 16, 2026
- Haṭhayogapradīpikā of Svātmārāma, Sanskrit text (GRETIL) checked October 16, 2026
- Gorakṣaśataka, edition Kuvalayananda and Shukla, verses 18-22, Sanskrit text (GRETIL) checked October 16, 2026
- Śrīśa Chandra Vasu (tr.), The Siva Samhita, Sacred Books of the Hindus vol. XV (1914-1915), Internet Archive checked October 16, 2026
- Arthur Avalon, The Serpent Power (1919): Ṣaṭ-cakra-nirūpaṇa, online edition (Wisdom Library) checked October 16, 2026