ERS | monograph Preface Tobias Welte, Editor in Chief Pulmonary diseases affect millions of patients every year world- wide. COPD, asthma and allergies are among the most wide- spread, affecting more than 5% of the total population. Diseases induced by cigarette smoke, such as chronic bronchitis, COPD and lung cancer, can be avoided, but intense social and political engagement is required in order for disease prevention pro- grammes to succeed. Research into the pathophysiology and genetics of pulmonary diseases has increased greatly in the last decade. This has led to new developments in lung cancer treatment and new therapies for asthma in addition, COPD and interstitial lung fibrosis have been evaluated and are now included in treatment guidelines. The level of development in this area of respiratory medicine is highlighted by the establishment of the first causal therapy for cystic fibrosis with genetic modifiers, and the improvement in long-term prognosis in pulmonary hypertension patients using a combina- tion of various drugs. In the past, treatment of respiratory conditions took place outside the major cities, mainly because TB was one of the major diseases. Pneumology was therefore only marginal a part of internal medicine. Fortunately, this has gradually changed over the years, in some countries more than others. Today, pneumology is almost at the centre of internal medicine. This opens new fields of interest where respiratory medicine overlaps with many other disciplines. Some of the most important areas of overlap are: oncology in the field of thoracic neoplasms cardiology for pulmonary hypertension infectious diseases connected with pneumonia and TB intensive care for patients with respiratory failure and the severely ill dermatologists and ear, nose and throat specialists in allergology neurologists and psychiatrists in sleep medicine and geriatricians and palliative care physicians involved in the care of patients with terminal illnesses. This issue of the ERS Monograph demonstrates the development of respiratory medicine convincingly. It provides an overview of Copyright ERS 2014. Print ISBN: 978-1-84984-052-1. Online ISBN: 978-1-84984-053-8. Print ISSN: 2312-508X. Online ISSN: 2312-5098. ERS Monogr 2014 65: ix–x. DOI: 10.1183/2312508X.10008514 ix