Relatively little attention has been directed toward damage inflicted upon the airway network that connects the alveoli, or toward the problems caused by invasive ventilation for patients with severe airflow obstruction. Mechanical ventilation with positive pressure can cause non-edematous barotrauma, inflict airway injury, and promote lung remodeling. Interactions between patient and ventilator, largely mediated through dynamic hyperinflation, include functional consequences for hemodynamics, respiratory muscle function, breathing work load, and patient-ventilator synchrony. Awareness of such associations not only helps to avoid complications during and after the critical phase of obstructive illness, but also opens a window to improved patient comfort and safety. The purpose of this review is to survey the range of structural damages and functional impairments that occur in an "obstructive" context.