Garudapurana 1.168.16

1.168.16

vāyuḥ śīto laghuḥ sūkṣmaḥ svaranāśīsthiro balī /
pittamamlakaṭūṣṇañcāpaṅktī rogakāraṇam //

Vāyu is cold, light, subtle, unsteady, mobile, and strong; / pitta is sour, pungent, hot, and indigestion is the cause of disease;