What is Emphysema?

QUESTION: I keep reading the term, but have absolutely no idea what it refers
to. Perhaps you can help. What is emphysema? How is it treated?
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ANSWER: Emphysema is a lung condition that is marked by shortness of breath.
It is diagnosed when the small air sacs that make up our lungs have become
weakened and lose their elasticity. Normally, these sacs, called alveoli,
expand with each breath and then return to their normal small size between
breaths. In emphysema, each sac is stretched out like an old balloon and do
not return to a small size. In addition to being stretched out, the weakened
alveoli don't exchange carbon dioxide for oxygen as they should.
Because the alveoli are not working properly, the respiratory muscles of
the chest must work harder. This leads to a barrel-chested appearance in many
emphysema sufferers. They also lose weight and tire very easily.
Emphysema has a biochemical cause that is created or worsened by
environmental factors. Normally, chemicals called proteases fight off
bacteria and viruses in the lung and are regulated by another chemical called
alpha-1-antitrypsin. In emphysema, alpha-1-antitrypsin is inactivated or
missing and the proteases go wild and start to attack healthy lung tissue.
Smoking inactivates alpha-1-antitrypsin, which is why smoking is the leading
cause of emphysema. Some cases of emphysema are related to genetic
biochemical defects, however.
There is no treatment for emphysema nor is there any way to reverse the
damage once it has begun. However, stopping smoking will prevent lung damage
from progressing.