Nadi Shodhana — Classical Alternate-Nostril Breathingpranayama classicalThe classical technique closes one nostril at a time using the fingers, breathing alternately through each side in a fixed pattern, on the premise that this directly balances the two channels rather than simply distracting from anxious thought. The Hatha Yoga Pradīpikā describes this practice, done seated and unhurried, as steadying the mind by steadying the breath first — the mind is treated as following the breath's pattern, not the other way around.What it's for

Medical Anxiety — Waiting for a procedure is read here as the activating channel of the breath running without a counterweight — the body preparing for something it cannot act on, with nowhere for that preparation to go. The practice makes no claim on the procedure or on its outcome, which belong to the people carrying it out. It asks only for the breath to be evened between both sides, slowly and deliberately, which the texts hold to settle the state the waiting produces.

Performance Anxiety — Classical prāṇāyāma reads the state before a performance as one side of the breath having taken over. The texts describe two channels, one activating and one settling, and treat the keyed-up, racing quality as the activating side running unregulated. The response is not to talk yourself down but to even the breath between both nostrils, on the understanding that the state follows the breath rather than the other way round.