Could you explain what is chronic obstructive lung disease?

COPD: These are diseases of respiratory system in which air is trapped in the lungs. In majority if not all of them airways are involved. Asthma, COPD and emphysema are part of it. In emphysema lung parenchyma is also affected by loosing elasticity. Cause is usually unknown, could be smoke related, genetic or as part of other disease such as rheumatoid arthritis, or auto immune disease. Shahzeidi, md.