COPD Overview and Definitions


Defining “Chronic Obstructive Pulmonary Disease (COPD)”
Author: Yan Yu Reviewers: Jason Baserman, Jennifer Au, Ciara Hanly, Zesheng Ye (叶泽生), Yonglin Mai (麦泳琳)*, Naushad Hirani*, Juri Janovcik* * MD at time of publication
Cystic Fibrosis
Multisystem disease due to CFTR gene mutation, that presents in the lungs as bronchiectasis
Bronchiectasis, Cystic Fibrosis, etc
Systemic disease, largely manifesting as an airflow-obstructing respiratory disorder; can manifest in the form of any of the following disorders:
Lung tissue destruction & abnormal, permanent enlargement of lung acini: airspaces distal to terminal bronchioles
Chronic Bronchitis
Chronic, productive cough for a total duration of 3 months per year, over 2 continuous years
Asthma that does not
remit completely with treatment (thus, chronic airflow obstruction) is defined as asthma-COPD overlap syndrome (ACOS)
Destruction and widening of large airways, resulting in mucus hyper-secretion and recurrent infections
Chronic Bronchitis
Most common COPD manifestations
(most patients suffer from a combination of emphysema and chronic bronchitis)
Clinically, COPD is seen as:
• Progressive, partially reversible airflow obstruction and lung hyperinflation (causing respiratory symptoms like cough, sputum production, and dyspnea)
• Post-bronchodilator spirometry results: FEV1/FVC ratio <0.7 (FEV1 is not a defining feature of COPD, but a marker of severity) • ↑ frequency & severity of acute exacerbations • Systemic manifestations such as deconditioning and muscle weakness Chronic Obstructive Pulmonary Disease (COPD) Asthma Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published January 7, 2013, updated October 5, 2021 on