The exact causes is still not known but it is believed to be caused by inhalation of polutant. These stuffs cause immune reaction that somehow destroy your alveoli.
And/or smoking can cause emphysema, weakening/eating away the thin skin tissue of your lungs.
emphysema
The related link below will tell you everything about emphysema, causes and treatment.
Heavy cigarette smoking causes about 80-90% of all emphysema cases
Nicotine
The answer is: Tar
emphysema
the toxins destroy you lungs and immune system.
emphysema
emphysema
emphysema
People with this type of emphysema have a hereditary deficiency of a blood component, an enzyme inhibitor called alpha-1-antitrypsin
Emphysema causes a higher breathing rate. A person with emphysema can be "air hungry" even when getting external oxygen by mask or cannula.