In High-Income Countries
Tobacco smoking is a major risk for COPD in these countries. About 80-95% of those diagnosed with this disease are active smokers or smoked in the past. Your risk of coming down with COPD depends on your level of exposure to tobacco smoke. However, the absence of a gene has been discovered in humans that could determine your susceptibility to COPD.
Women, in general, are more likely to come down with COPD than men because they are at more risk of the deleterious effects of smoke than men. In people who do not smoke, they can come down with COPD by inhaling cigarette smoke from the cigarette of smokers. This is referred to as second-hand smoking and it causes about 20% of cases of COPD. Note that marijuana, water-pipe smoke can predispose one to COPD too.