TY - CHAP M1 - Book, Section TI - Chronic Obstructive Pulmonary Disease A1 - Silverman, Edwin K. A1 - Crapo, James D. A1 - Make, Barry J. A2 - Jameson, J. Larry A2 - Fauci, Anthony S. A2 - Kasper, Dennis L. A2 - Hauser, Stephen L. A2 - Longo, Dan L. A2 - Loscalzo, Joseph Y1 - 2018 N1 - T2 - Harrison's Principles of Internal Medicine, 20e AB - Chronic obstructive pulmonary disease (COPD) is defined as a disease state characterized by persistent respiratory symptoms and airflow limitation that is not fully reversible (http://www.goldcopd.com/). COPD includes emphysema, an anatomically defined condition characterized by destruction of the lung alveoli with air space enlargement; chronic bronchitis, a clinically defined condition with chronic cough and phlegm; and small airway disease, a condition in which small bronchioles are narrowed and reduced in number. The classic definition of COPD requires the presence of chronic airflow obstruction, determined by spirometry, that usually occurs in the setting of noxious environmental exposures—most commonly cigarette smoking. Emphysema, chronic bronchitis, and small airway disease are present in varying degrees in different COPD patients. Patients with a history of cigarette smoking without chronic airflow obstruction may have chronic bronchitis, emphysema, and dyspnea. Although these patients are not included within the classic definition of COPD, they may have similar disease processes. Respiratory symptoms and other features of COPD can occur in subjects who do not meet a definition of COPD based only on airflow obstruction determined by spirometric thresholds of normality. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/10/11 UR - accessmedicine.mhmedical.com/content.aspx?aid=1156756504 ER -