Prolonged expiration

An abnormal lengthening of the expiratory phase of breathing (>5 seconds) due to airflow limitation, increased airway resistance (airway narrowing), or reduced elastic recoil.

Causes

• Obstructive airway diseases (airway narrowing)

  • Asthma

  • Chronic obstructive pulmonary disease (COPD)

  • Chronic bronchitis

  • Emphysema

  • Bronchiolitis

• Large airway disorders

  • Tracheomalacia

  • Excessive dynamic airway collapse

  • Endobronchial obstruction

  • Foreign body aspiration

  • Tracheal or bronchial stenosis

• Small airway diseases

  • Bronchiolitis

  • Constrictive bronchiolitis

  • Small airway inflammatory disorders

• Allergic and inflammatory causes

  • Allergic airway inflammation

  • Hypersensitivity reactions affecting bronchi

  • Eosinophilic airway disease

• Environmental and exposure-related causes

  • Tobacco smoke exposure

  • Occupational inhalational irritants

  • Air pollution

• Neuromuscular weakness impairing effective expiration

• Obesity-related airway restriction (occasionally contributing to prolonged expiration)