This book presents an authoritative yet accessible account of this complex area, fusing the basic principles of respiratory physiology with applications in clinical practice across a wide range of disorders. This third edition has been extensively revised to reflect advances in our understanding of respiratory function at rest, on exercise and during sleep, together with technological developments related to investigation and treatment. Now subdivided into four practical sections, users can easily pick their desired topic, from the commonly used tests and their underlying physiological mechanisms to abnormalities of function in both respiratory and non-respiratory diseases. The book concludes with a helpful section on test interpretation, new to this edition.