Alternate Nostril Breathing

Nadi Shodhana, commonly translated as alternate nostril breathing or channel purification, is described in the second chapter of the Hatha Yoga Pradipika as a technique of inhaling through one nostril, retaining the breath, and exhaling through the other, then reversing the pattern on the following breath. The Gheranda Samhita describes a closely related technique under the name Nadi Shuddhi, with broadly similar aims, and together these two texts establish alternate nostril breathing as one of the foundational pranayama practices in the classical hatha curriculum.

The stated purpose of the practice, in the tradition's own terms, is purification of the nadis, the network of subtle channels the tradition describes as carrying prana throughout the body. The texts describe two principal channels, ida and pingala, associated respectively with the left and right nostrils and with complementary qualities the tradition frames as cooling and heating, or lunar and solar. Nadi Shodhana is presented as balancing the flow of prana between these two channels, a prerequisite the Hatha Yoga Pradipika considers necessary before a practitioner attempts more demanding pranayama, on the traditional premise that an imbalance between the channels leaves the practitioner's energy system unsteady and unready for deeper retention.

Because it is comparatively gentle in comparison to techniques like Bhastrika or Kapalabhati, Nadi Shodhana is often taught early in a pranayama curriculum and is one of the most widely practiced breathing techniques in contemporary yoga generally, frequently offered without extensive prerequisite training. Traditional sources, however, still describe a progression: a simple version practiced without retention is generally taught first, with breath retention (kumbhaka) added only once the basic alternating pattern is smooth, even, and comfortable, and the classical locks may be incorporated by more advanced practitioners once retention itself is well established.

The hand position traditionally used, employing the thumb and ring finger of the right hand to alternately close each nostril while the remaining fingers rest gently, is sometimes called Vishnu Mudra in later manuals, though the classical texts themselves are less concerned with naming the hand shape than with the quality of the breath it enables: slow, smooth, and free of any audible strain or gasping at either end of the cycle.

Alternate nostril breathing has a modest but genuinely useful evidence base compared to many classical practices, with a number of studies examining its short-term physiological effects. Several of these report reductions in heart rate and blood pressure, and decreases in self-reported anxiety, measured shortly after a session of practice, findings that are broadly consistent with what is known more generally about slow, controlled breathing's effects on the autonomic nervous system, shifting activity toward the calmer, parasympathetic branch.

It is worth being precise about what this research can and cannot attribute these effects to. The slow, even pacing of the breath, common to many pranayama techniques regardless of which nostril is used, is a more parsimonious explanation for the observed calming effects than the specific alternation between nostrils; studies that have tried to compare nostril-alternating breathing to simple slow breathing without alternation generally find similar calming effects for both, suggesting the pacing, not the switching, is doing most of the work physiologically.

The traditional claim that Nadi Shodhana purifies subtle channels called nadis, or balances complementary energetic qualities associated with each nostril, belongs to the tradition's own explanatory framework and is not a claim that contemporary physiology can test or confirm; this article reports it as traditional understanding rather than scientific finding. What can fairly be said is that Nadi Shodhana, understood simply as a slow, even, alternating breathing pattern, sits among the better-supported classical techniques for short-term calming effects, even without accepting its traditional energetic explanation.

1. Sit comfortably with an upright, relaxed spine, resting the left hand on the left knee.
2. Bring the right hand up, folding the index and middle fingers into the palm, leaving the thumb and ring finger free to close each nostril in turn.
3. Close the right nostril with the thumb and inhale slowly and smoothly through the left nostril.
4. Close the left nostril with the ring finger, release the thumb, and exhale slowly through the right nostril.
5. Inhale through the right nostril, then close it with the thumb, release the ring finger, and exhale through the left nostril.
6. Continue alternating in this pattern, treating one full inhale-exhale-inhale-exhale sequence as a complete round.
7. Practice five to ten rounds, keeping the breath smooth, quiet, and unforced throughout, without introducing retention until the basic pattern feels entirely comfortable.
8. Finish with a few breaths through both nostrils and a short period of quiet sitting before resuming ordinary activity.

Nadi Shodhana in its gentle, no-retention form is one of the more accessible pranayama practices, but breath retention should not be added forcefully by anyone who is pregnant, or who has uncontrolled high blood pressure or heart disease; the gentle, no-retention version described above is the appropriate choice in these situations, and any addition of retention should only be considered with individualized guidance from a qualified teacher. If nasal congestion makes breathing through one nostril genuinely difficult, do not force air through a blocked passage; either practice on the days when breathing is clear, or use a gentler approach that does not require full nostril closure until congestion resolves. Stop and return to normal breathing if you feel light-headed, anxious, or short of breath at any point, treating discomfort as a signal to ease off the pace or duration rather than to push through it.