Nonorganic upper airway obstruction.

Two cases of severe dyspnea and stridor with upper airway obstruction of obscure origin are discussed. Complete medical evaluation could identify no organic cause for the symptoms, and functional upper airway obstruction was diagnosed. Treatment with psychotherapy and relaxation techniques was successful. Diagnosis can be made with pulmonary function studies. Flow-volume loops may show a lower inspiratory vital capacity than expiratory vital capacity and a discrepancy between inspiratory flow limitation and airway resistance. It is important to establish a functional etiology to prevent unnecessary treatment and provide proper care.