Kundalini

Kundalini (कुण्डलिनी, "the coiled one") is, in the tantric and Hatha-Yogic systems, the latent energetic potential at the base of the spine — depicted as a serpent coiled three and a half times around the Muladhara chakra. When awakened by sustained practice, the serpent uncoils and ascends through the Sushumna (the central energetic channel) to the crown.

The ascent is not a single event but a graded refinement. Each chakra along the spine is a transformation point: the energy is refined at Svadhisthana, again at Manipura, again at Anahata, and so on. Different Tantric and Hatha-Yogic schools describe the path and the awakening variously, but the through-line is consistent: by the time the ascent reaches Sahasrara at the crown — reading the Tantric/HYP ascent together with the Ayurvedic dhatu chain — what began as densified reproductive essence (shukra or rajas) has become ojas, the most refined form available to the human body. The shukra/rajas → ojas mapping is a cross-system synthesis drawn from Tantric and Ayurvedic sources read together, not a single verbatim claim in either system alone.

The channel system

• Sushumna — the central channel along the spine; the route of the ascent
• Ida — the lunar channel, weaving to the left, terminating at the left nostril
• Pingala — the solar channel, weaving to the right, terminating at the right nostril

Ida and Pingala interweave around Sushumna in a double-helix pattern (visually echoed in the caduceus, though the two symbol systems have independent histories). Balancing the two side channels via nadi shodhana (alternate-nostril breathing) is one of the preliminary practices that prepares Sushumna to open.

Primary sources

• Sat Chakra Nirupana (16th c., translated by Arthur Avalon as The Serpent Power) — the canonical Sanskrit treatise on the chakra-channel system — Internet Archive
• Hatha Yoga Pradipika, chapter III (On Mudras and Bandhas, verses 1–5 framing the chapter, particularly the discussion of kundalini at III.1–6 and the mudras following) — mudras and bandhas framed as practices for kundalini awakening — Sacred Texts
• Gheranda Samhita, chapter III (On Mudras) — twenty-five mudras, several explicitly aimed at rousing kundalini (e.g. III.45–48 on shakti chalini mudra)
• Shiva Samhita, chapters III–V — nadi system, chakra descriptions, and kundalini practices within the broader Tantric frame
• Yoga Yajnavalkya — an older classical yoga text with systematic treatment of the nadis and a brief discussion of kundalini in its closing chapter — Wisdomlib

In motion

• The redirection mechanism is, on this site's reading, the technical heart of brahmacharya.
• The seed-drop that ascends is bindu in Tantric usage; what it becomes at the crown, read across into the Ayurvedic vocabulary, is ojas.
• The Taoist parallel — the microcosmic orbit — performs an analogous circulation of vital essence through a different anatomical map (a continuous governing/conception-vessel loop rather than a one-directional ascent through a central channel) and different conceptual language.