BackgroundChronic respiratory disease burden in Nepal is high, although data from the Terai (lowlands) is limited.MethodsThrough a community outreach programme in Mechinagar, 3398 adults (mean age 49.6 years, 59% female) were recruited to complete spirometry and questionnaires to determine prevalences of airflow obstruction, breathlessness (MRC dyspnoea score ≥3) and self-reported chronic lung disease. Multivariate logistic regression examined associated demographic and lifestyle factors.ResultsPrevalences of airflow obstruction (15%) and breathlessness (13%) exceeded self-reported chronic lung disease (8%). Age (odds ratio = 1.06, 95% confidence interval = 1.05-1.07), body mass index (BMI) per 1 kg/m2 (0.90, 0.88-0.93), physical inactivity (1.95, 1.07-3.84) and no formal education (1.46, 1.14-1.88) were associated with airflow obstruction. Smoking was only associated with airflow obstruction in females (1.90, 1.22-2.94) and adults ≥40 years (1.40, 1.05-1.86). Age (1.04, 1.03-1.05), airflow obstruction (2.43, 1.85-3.18), and male sex (0.63, 0.49-0.80) were associated with breathlessness. Only in females was breathlessness associated with BMI (1.08, 1.05-1.12) and mixed biomass use (2.65, 1.39-4.85). In men, labour/farming/agriculture work (3.30, 1.12-14.20) or unemployment (4.39, 1.43-19.30) was associated with breathlessness.ConclusionThere is likely underdiagnosis of chronic lung disease in the Terai. Addressing smoking, educational disparities, physical inactivity and environmental pollutant exposure are public health priorities to improve respiratory health in the region.