| Neuromuscular disease | 156 |
| Dyspnoea of unknown origin | 94 |
| Chronic obstructive pulmonary diseases (COPD) | 45 |
| Rheumatological disease | 37 |
| Chest wall disease (acquired and congenital) | 22 |
| Other restrictive lung diseases | 15 |
| Obesity hypoventilation | 14 |
| Malignancy | 7 |
| Others | 23 |