| Pulmonary function | FEV1 | Decreased |
| FVC | Decreased | |
| Total lung capacity | Unchanged | |
| Functional residual capacity | Increased | |
| Residual volume | Increased | |
| FEV1/FVC | Decreased | |
| Peak flow rate | Decreased | |
| Anatomical change | Air space size | Increased |
| Chest wall compliance | Decreased | |
| Total respiratory system compliance | Decreased | |
| Elastic recoil | Decreased | |
| Respiratory muscle strength | Transdiaphragmatic pressure | Decreased |
| Maximal inspiratory pressure | Decreased | |
| Maximal expiratory pressure | Decreased | |
| Maximal voluntary ventilation | Decreased | |
| Gas exchange | Diffusing capacity for carbon monoxide | Decreased |
| Defensive mechanism and regulation of breathing | Cough ability | Decreased |
| Cough reflex | Decreased | |
| Responses to hypoxia and hypercapnia | Decreased | |
| Reactivity to airway resistance | Decreased | |
| Minute ventilation | Unchanged | |
| Tidal volume | Decreased | |
| Respiratory rate | Increased | |
| Immunology (Bronchoalveolar lavage) | Proportion of macrophages | Decreased |
| CD4+/CD8+ ratio | Increased | |
| IgA and IgM | Increased | |
| Exercise capacity | Maximum oxygen consumption | Decreased |
| Dead space ventilation | Increased | |
| Responses to hypercapnia during exercise | Increased |