or physical aging. Historically, men were more commonly afflicted than women, but as it has become more common for women to smoke tobacco in developed nations, as well as being exposed to indoor air pollution in lower-income countries, women and men are affected almost equally. Interestingly, some studies have shown that women may be more susceptible to developing COPD and emphysema. 11 , 12 Risk is also increased in patients with genetic conditions such as alpha-1 antitrypsin deficiency, in which patients lack a major inhibitor of serine proteases, 13 which may