[The effects of smoke on airways]

Among the numerous effects of tobacco smoke on airway mucosa, the best known and the most frequent are those leading to chronic bronchitis (CB) or chronic obstructive pulmonary disease (COPD). Recent studies suggest that inflammation is central to these disorders. If predominant in larger airways (diameter greater than 4 mm), inflammation is associated with CB. When predominant in small airways (diameter less than 2 mm), it can induce COPD. The exact mechanisms remain unknown. There is no useful way in early detecting evolution toward COPD in asymptomatic smokers.