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Updated September 13, 2013.

Definition:
Emphysema is a severe form of COPD, in which the tiny air sacs (alveoli) in the lungs become permanently damaged. Normal, healthy lungs look like upside down branches of a tree with many thousands of these tiny air sacs at the ends of those branches. Lungs with emphysema have fewer, larger air sacs.

While environmental pollution can cause emphysema, cigarette smoking is by far the most common cause.


The chemicals in cigarette smoke are thought to damage the delicate, interconnecting walls of tiny alveoli, breaking them down in to large air sacs that are less efficient at processing the exchange of oxygen and carbon dioxide that allows us to breathe properly.

The effects of emphysema are permanent and irreversible. However, if a person stops smoking soon enough, they may be able to arrest further damage and improve their lung function to some extent.