The latest study investigating association between different smoking statuses and survival and emphysema in COPD patients found that current or continued smokers have the worst pulmonary function, suggesting a more important destruction of the lung parenchyma, while AECOPD without smoking risk mostly affects the airways. The study by a team of researchers from various departments at The Ninth Hospital Affiliated with Xi’an Jiaotong University, showed that lung diffusion dysfunction (oxygen diffusion problems through the alveolar membrane) in the smokers was more obvious, inferring that lung parenchymal damage such as alveolar tissue was more serious than in non-smokers. On the other hand, AECOPD in non-smokers appeared to involve airway resistance more than alveolar damage.