What causes COPD?

COPD is usually caused by long-term exposure to irritants that damage your lungs and airways. In the US, cigarette smoke is the main cause. Inhaling other types of smoke (pipe, cigar, biomass fuel, etc), pollution, and chemical fumes can also cause COPD. Also, some people have a genetic condition called alpha-1 antitrypsin deficiency which makes them more likely to sustain lung damage from pollution and smoke and sometimes lead to early-onset COPD.^[1]