With correct practice of prāṇāyāma, all diseases are destroyed. With incorrect practice, all diseases arise.

A verse of absolute clarity about the duality of prāṇāyāma: it is medicine or poison depending on how it is used.

Yuktena (correctly, appropriately) leads to sarva-roga-kṣaya — the destruction of all diseases. Ayukta (incorrect) produces sarva-roga-samudbhava — the arising of all diseases.

The symmetry of the verse is deliberate: the same practice has diametrically opposite effects depending on its execution.

What makes practice “correct”?

• Gradual progression (previous verse)
• Guidance from a qualified teacher (2.1)
• Stable āsana established
• Appropriate diet
• Proper proportions of pūraka, kumbhaka, recaka
• Attention to the body’s signals

This verse reinforces why traditional texts insist on guru-śiṣya transmission for advanced prāṇāyāma.