摘要Objective Pulmonary arterial hypertension(PAH)poses a growing global health challenge,yet comprehensive epidemiologi-cal data remain limited.This study aims to assess the burden of PAH from 1990 to 2021 and project trends to 2040,addressing critical gaps in incidence,mortality,and disability-adjusted life years(DALYs)across diverse socio-demographic contexts.Methods Using data from the Global Burden of Disease(GBD)2021 study,we analyzed PAH burden across 204 countries and territories,stratified by age,sex,region,and socio-demographic index(SDI).Age-standardized rates(per 100,000 populations)for incidence(ASIR),mortality(ASMR),and DALYs(ASDR)were calculated.Future trends were projected via a Bayesian age-period-cohort(BAPC)model.Results In 2021,there were 43,251(95％uncertainty interval[UI]:34,705,52,441)global incident PAH cases(age stand-ardized incidence rate[ASIR]:0.52).From 1990 to 2021,PAH incidence rose by 85.62％,with the steepest increase in high-middle SDI regions(average annual percentage change[AAPC]:+0.19％).Despite a 48.36％rise in deaths,the age-standardized mortality rate(ASMR)declined annually by 0.84％,reflecting improved management.Central Europe had the highest ASMR(1.06 per 100,000),while low SDI regions showed reduced ASIR(-0.31％AAPC),likely due to underdi-agnosis.PAH caused 642,104 DALYs globally in 2021,with infants(＜1 year)bearing the highest DALY rate.Projections indicate 75,000 annual cases by 2040,emphasizing an escalating burden.Conclusion PAH burden is increasing disproportionately in aging populations and high-middle SDI regions,while low SDI areas face underdiagnosis and healthcare disparities.Targeted interventions,equitable resource allocation,and enhanced diagnostic capacity are urgently needed to mitigate future PAH-related morbidity and mortality.