Introduction
In yogic tradition, the choice of which nostril to begin pranayama is not arbitrary. Each nostril corresponds to a specific nāḍī (energy channel):
- Left nostril (Idā nāḍī): Cooling, calming, lunar, associated with the parasympathetic system.
- Right nostril (Piṅgalā nāḍī): Heating, activating, solar, associated with the sympathetic system.
- Both nostrils (Suṣumṇā nāḍī): Balance, spiritual awakening.
Thus, deciding the starting nostril helps tune the practice to the practitioner’s energy, environment, and time of day.
1. General Rule in Anuloma-Viloma (Alternate Nostril Breathing)
- Traditionally, pranayama begins with inhalation through the left nostril (Idā) and ends with exhalation through the left.
- This is because:
- Left nostril activation calms the body and mind.
- It prepares the practitioner for deeper concentration.
- It ensures a balanced start, especially for beginners.
2. Exceptions and Variations
- Morning practice (before sunrise): Often begins with the left nostril to create calmness and sattva.
- Cold weather / lethargy / dullness: One may start with the right nostril (Piṅgalā) to energize and warm the body.
- Hot weather / restlessness / anxiety: One may start with the left nostril (Idā) to cool and calm.
- Before meditation: Always best to start with the left nostril to quiet the mind.
- Advanced pranayama (e.g., Sūrya Bhedana or Candra Bhedana): The starting nostril is determined by the type of practice:
- Sūrya Bhedana → Inhale through right (Piṅgalā).
- Candra Bhedana → Inhale through left (Idā).
3. Scriptural Guidance
- Haṭha Yoga Pradīpikā (Chapter 2) prescribes beginning alternate nostril breathing with the left nostril.
- Commentaries explain that since the left channel is cooling and stabilizing, it provides a safe entry into pranayama for all levels.
Conclusion
In most pranayama practices—especially Anuloma-Viloma—the breath should start from the left nostril and end at the left. However, variations are applied based on time, season, health, and the specific technique. The guiding principle is to maintain balance of Idā and Piṅgalā and prepare the mind for stillness.