In general samprapti of Kasa, which action drives lung involvement?

• A. Apana pushing Udana into the lungs
• B. Prana pushing Udana into the lungs
• C. Udana pushing Prana into the lungs
• D. Sadhaka Pitta moving Kapha

Answer: (A)

In this topic, the movement of the five prana-vayus within the pranavaha srotas governs how a cough (Kasa) develops. Udana vayu directs respiration and the chest region, while Apana vayu moves downward. When the downward force of Apana vayu pushes Udana vayu into the lungs, Udana’s influence acts within the lungs to drive respiratory activity and the cough reflex. This interaction brings lung involvement into the disease process, especially in the setting of Kapha obstruction that accompanies Kasa. The other proposed interactions don’t describe this primary vayu-driven mechanism in which Apana forces Udana into the lungs, so they don’t fit as the main driver of lung involvement.