Conceptually unsavoury, airway mucus is vital to homeostasis in the respiratory tract. In contrast, when abnormal, mucus contributes significantly to the pathophysiology of a number of severe bronchial diseases, including asthma, chronic bronchitis and cystic fibrosis. This volume provides wide ranging and in-depth coverage of the scientific and clinical aspects of airway mucus. It commences with introductory chapters which address the biochemical and molecular biological basis of airway mucus and continues with comprehensive coverage of the various physiological and rheological aspects of respiratory secretions. The clinical aspects of the topic are then considered, with chapters discussing the involvement of mucus secretions in bacterial infection and in hypersecretory diseases of the airway. The volume concludes with a discussion of the therapeutic aspects of the topic, both in terms of the possible approaches to the treatment of mucus hypersecretion and the interaction of these drugs with airway mucus. Written by leading experts in the field, each contribution provides a comprehensive review of its particular subject. Reflecting the latest advances in this important area of respiratory research, this volume will be of great interest to scientists and clinicians working in the field of airway secretions and related areas.