Book excerpt: Chronic Obstructive Pulmonary Disease (COPD) represents an important public health challenge and is a major cause of chronic morbidity and mortality throughout the world. COPD is currently the fourth leading cause of death in the world1 but is projected to be the 3rd leading cause of death by 2020. More than 3 million people died of COPD in 2012 accounting for 6% of all deaths globally. Globally, the COPD burden is projected to increase in coming decades because of continued exposure to COPD risk factors and aging of the population.2 This Pocket Guide has been developed from the Global Strategy for the Diagnosis, Management, and Prevention of COPD (2018 Report), which aims to provide a non-biased review of the current evidence for the assessment, diagnosis and treatment of patients with COPD that can aid the clinician. Discussions of COPD and COPD management, evidence levels, and specific citations from the scientific literature are included in that source document, which is available from www.goldcopd.org. The tables and figures in this Pocket Guide follow the numbering of the 2018 Global Strategy Report for reference consistency.