Diseases of the respiratory system are the most frequently encountered problem in the childhood years. Paediatric respiratory medicine is a rapidly growing field and one in which there is a constant flow of new investigative techniques and treatments available for even the smallest of patients. Examples of this include rapid techniques for viral or bacterial diagnosis, increasingly sophisticated and less invasive methods for measuring pulmonary function and for imaging of the respiratory system, new antibiotics for serious infections and the availability of improved prenatal diagnosis by chorionic villous sampling, amniocentesis or ultrasound for an increasing number of respiratory conditions including cystic fibrosis. This textbook is designed to give a basic overview of the subject, to highlight areas of recent advance and to point the reader to appropriate references and recommended reading if he or she wishes to deepen their knowledge further in any particular area. It is aimed primarily at those who have recently entered the field, interested General Practitioners and particularly those who are preparing for the MRCP. It is hoped that it may also be of interest to others such as paediatirc nurses and physiotherapists who frequently deal with children in hospital because of their respiratory problems.