RT Book, Section A1 Kemp, Walter L. A1 Burns, Dennis K. A1 Brown, Travis G. SR Print(0) ID 57053485 T1 Chapter 13. Pulmonary Pathology T2 Pathology: The Big Picture YR 2008 FD 2008 PB The McGraw-Hill Companies PP New York, NY SN 978-0-07-147748-2 LK accessphysiotherapy.mhmedical.com/content.aspx?aid=57053485 RD 2024/03/29 AB Diseases of the lung can be classified into four general categories: (1) obstructive lung disease; (2) restrictive lung disease; (3) infectious disease; and (4) neoplastic disease (Table 13-1). The key clinical difference between obstructive and restrictive lung disease is the forced expiratory volume at one second (FEV1) and the forced vital capacity (FVC) ratio, which is decreased in obstructive lung disease and normal in restrictive lung disease. In obstructive lung disease, air is trapped within the parenchyma; in restrictive lung disease, airway filling is impaired due to fibrosis of alveolar septae. The four main types of obstructive lung disease are emphysema, asthma, bronchiectasis, and chronic bronchitis. Restrictive lung disease can be divided into acute and chronic forms, and chronic forms can be subdivided by etiology (i.e., work related, drug induced, autoimmune, and idiopathic).