Chronic obstructive pulmonary diseases (COPD)-3 in previous 2 discussions we have discussed Definition of COPD ASTHMA Bronchiectasis Chronic Bronchitis so today we will continue our discussion with Emphysema A permanent dilatation of any part of the air spaces distal to the terminal bronchiole with destruction of tissue but no scarring. It is a common condition with increasing incidence with age, and is more common in males than in females. Pathogenesis: The imbalance of protease-antiprotease and oxidant-antioxidant Current opinion favors emphysema arising as a consequence of two critical imbalances: the protease-antiprotease imbalance and oxidant-antioxidant imbalance Chronic bronchitis The destructive structure of airway wall The mucus plug Destruction of respiratory tissue leads to a loss of elastic recoil in the lungs and a decreased area available for gas exchange. α1-antitrypsin inactivated or absent, resluting in continued ...