The airway disease termed asthma has been recognized for centuries but is now receiving increased attention because of chronicity, high incidence in the population and rising mortality rate. Asthma is now recognized as a disease of unknown etiology characterized by a hyperactive airway which can be demonstrated by research techniques or is readily apparent during clinical observations. The role of bioactive mediators in inducing asthma or its basic abnormality, the hyperactive airway, is a major research target as are the roles of neurokinins and inflammation. Management of asthma varies with experience, training and locale of the physician, and various types of available pharmacologic preparations are suitable for control of the intermittent wheezing of the mild asthmatic. As more severe asthma is encountered in individual patients, a more experienced physician and more intense therapy is required. The most severe form of asthma, characterized as PFA, requires intense therapy, close patient physician contact and further intense study, particularly of the psychosocial and economic patterns which interfere with optimal management.