Aetiology

Localised areas of emphysema may be caused by:

• congenital disorders
  
  
• compensatory changes:
  • lung collapse
  • scarring
  • resection
    
    
• partial bronchial occlusion:
  • foreign body
  • peribronchial lymphadenopathy
  • neoplasm
    
    
• in rare cases a unilateral emphysema may occur due to bronchiolitis before the age of 8 years
  
  
• smoking
  
  

Generalised:

• idiopathic / primary
  
  
• physiological (senile emphysema)
  
  
• familial:
  • alpha 1 anti-trypsin deficiency
  • lower lobes more severely affected
    
    
• associated with:
  • chronic bronchitis
  • chronic asthma
  • pneumoconioses