Inhalational injury to the respiratory tract is common and can be subtle. The clinical features produced by these injuries are very similar, and pulmonary function tests usually show an obstructive profile. Pathologic reactions also appear to be similar, with the end result airway distortion by inflammation and fibrosis. Rather than postulating that there is a specific airway response to each of a broad range of agents, it is more likely that inflammation and fibrosis are nonspecific and stereotypic responses.