Differential diagnosis of chronic obstructive pulmonary disease (COPD)
| Diagnosis | Suggestive features |
| COPD | Mid-life onset |
| Slowly progressing symptoms | |
| Long history of smoking | |
| Asthma | Early onset |
| Varying symptoms | |
| Symptoms during the night/early morning | |
| Presence of allergy, rhinitis and/or eczema | |
| A family history | |
| Airflow limitation that is largely reversible | |
| Congestive heart failure | Fine basilar crackles on auscultation |
| Dilated heart on chest radiography | |
| Peripheral oedema | |
| History of ischaemic heart disease | |
| Volume restriction not airflow limitation on pulmonary function tests | |
| Bronchiectasis | Large volume of purulent sputum |
| Commonly associated with bacterial infection | |
| Coarse crackles on auscultation | |
| Clubbing | |
| Bronchial dilation and bronchial wall thickening on chest radiography/CT | |
| Tuberculosis | Onset at all ages |
| Lung infiltrate on chest radiography | |
| Microbiological confirmation | |
| High local prevalence of tuberculosis | |
| Obliterative bronchiolitis | Younger onset and in nonsmokers |
| History of rheumatoid arthritis/fume exposure? | |
| Hypodense areas on expiration on CT | |
| Diffuse panbronchiolitis | Affects mostly male nonsmokers |
| Almost all have chronic sinusitis | |
| Diffuse small centrilobular nodular opacities and hyperinflation on chest  radiography and HRCT |
CT: computed tomography; HRCT: high-resolution computed tomography.