Box 2.

Comorbidities commonly reported in severe asthma.

< Rhinosinusitis/(adults) nasal polyps

< Psychological factors: personality trait, symptom perception, anxiety, depression

< Vocal cord dysfunction

< Obesity and physical deconditioning

< Smoking/smoking-related disease

< Obstructive sleep apnoea

< Hyperventilation syndrome

< Hormonal influences: premenstrual, menarche, menopause, thyroid disorders

< Gastro–oesophageal reflux disease

< Drugs including aspirin, non-steroidal anti-inflammatory