Causes of COPD exacerbations
| Bacteria |
| H influenzae |
| S pneumoniae |
| M catarrhalis |
| Staphylococcus aureus |
| P aeruginosa |
| Viruses |
| Rhinovirus (common cold) |
| Influenza |
| Parainfluenza |
| Coronavirus |
| Adenovirus |
| Respiratory syncytial virus |
| Picornavirus |
| Metapneumovirus |
| Atypical organisms |
| M pneumoniae |
| C pneumoniae |
| Pollutants |
| Nitrogen dioxide |
| Particulates (PM10) |
| Sulphur dioxide |
| Ozone |