The Compendium of Caraka 6.8.43

6.8.43

rasaḥ srotaḥsu ruddheṣu svasthānastho &vidahyate/
sa ūrdhvaṃ kāsavegena bahurūpaḥ pravatate//

When the channels are obstructed, the rasa staying in its own seat burns;
arising upward with the impulse of cough, it issues forth in many forms.