Emphysema affects numerous respiratory air volumes during a series of cascading events in a chain reaction, according to the Pulmonary Medicine journal. These events act to decrease elasticity, lowering the end elastic recoil of the lungs, which appears to first affect the end expiratory lung volume, or EELV.
The lungs aren't able to full deflate naturally, leaving trapped air behind, which then forces them to compensate by hyperinflating, explains Pulmonary Medicine. This in turn increases tidal volume, or VT. Resting lung volume and residual volume respond to the increased pressure brought on by the hyperinflation by generating ever more force. This ends up shortening the length of the muscles in the diaphragm, eventually weakening them, as they cannot fully contract and expand. The inspiratory reserve volume is also reduced, as a consequence of this cycle of lung destruction that, once set in motion, cannot be stopped.