Lung Function in COPD

^*In COPD, the extent of airway wall and alveolar changes varies among individuals. These changes do not always coexist and may progress at different rates over time.
FEV₁ , forced expiratory volume in 1 second.

^*COPD curve is typical but not universal. 
CT, computed tomography; DLCO, diffusing capacity of the lung for carbon monoxide; ERV, expiratory reserve volume; FEV₁ , forced expiratory volume in 1 second; FRC, functional residual capacity; FVC, forced vital capacity; IC, inspiratory capacity; IOS, impulse oscillometry; MIP/MEP, maximal inspiratory pressure/maximal expiratory pressure.