| 1) Rhinosinusitis/(adults) nasal polyps |
| 2) Psychological factors: personality trait, symptom perception, anxiety, depression |
| 3) Vocal cord dysfunction |
| 4) Obesity |
| 5) Smoking/smoking related disease |
| 6) Obstructive sleep apnoea |
| 7) Hyperventilation syndrome |
| 8) Hormonal influences: premenstrual, menarche, menopause, thyroid disorders |
| 9) Gastro-oesophageal reflux disease (symptomatic) |
| 10) Drugs: aspirin, non-steroidal anti-inflammatory drugs (NSAIDs), β-adrenergic blockers, angiotensin-converting enzyme inhibitors |