The World’s burden of chronic respiratory disease: An epidemiological review of asthma, COPD, interstitial lung disease, and smoking in the 21st century

• Asthma, COPD, ILD, and tobacco smoking collectively represent a substantial and growing global public health challenge. • These conditions share common risk factors and drivers, including environmental exposures and socioeconomic determinants. • Their future burden will be shaped by megatrends, including urbanization, climate change, population aging, and the global expansion of tobacco and nicotine product markets. • Respiratory health should be prioritized in global health agendas. Chronic respiratory diseases (CRDs) represent a substantial component of the global burden of disease, contributing significantly to morbidity, mortality, and healthcare expenditure worldwide. This review synthesizes current evidence on the epidemiology, determinants, and both population-level and individual impacts of four major respiratory health conditions: asthma, chronic obstructive pulmonary disease (COPD), interstitial lung disease (ILD), and smoking; the latter is both a disease in itself and a major contributor to respiratory and non-respiratory morbidity. Despite distinct pathophysiological mechanisms, these conditions share common risk factors, including environmental exposures and socioeconomic determinants, which contribute to diagnostic and management challenges. This review examines the burden of these conditions at both individual and population levels, explores current and future trends, and highlights the critical need for coordinated public health strategies, primary prevention, and global policy interventions to mitigate their growing impact. Considering the interconnections between human, animal, and environmental health, a unifying framework of planetary respiratory medicine and One Health may provide solutions to the CRD burden by promoting lung health across the life course.