Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disorder characterized by persistent synovial inflammation, progressive joint destruction, and significant extra-articular manifestations. As one of the most prevalent autoimmune diseases worldwide, RA contributes substantially to global disability, imposing heavy burdens on healthcare systems, economies, and patients' quality of life. Despite advances in therapeutic strategies, including the widespread adoption of disease-modifying antirheumatic drugs and biologic agents, RA continues to affect millions across diverse geographic and socioeconomic contexts. Understanding its evolving epidemiological landscape is crucial for informing public health policies and allocating healthcare resources. This study provides a detailed assessment of RA's global burden from 1990 to 2021 and projects trends to 2050.

We utilized data from the Global Burden of Diseases(GBD), Injuries, and Risk Factors Study (GBD) 2021. We estimated incidence, prevalence, mortality, and disability-adjusted life years (DALYs) for 204 countries and territories. Age-standardized rates were calculated and stratified by sex, Socio-demographic Index (SDI), and GBD super-regions. Temporal trends were quantified using Average Annual Percentage Change (AAPC), and future projections were modelled using the Bayesian Age-Period-Cohort (BAPC) framework.

In 2021, there were 1.00 million (95% UI: 0.90-1.11) global incident cases of RA (ASIR: 11.8 per 100,000) and 17.92 million (15.97-20.30) prevalent cases (ASPR: 208.9). RA resulted in 37,330 (31,060-43,136) deaths (ASMR: 0.45) and 3.08 million (2.31-3.97) DALYs (ASDR: 35.89). High Socio-demographic Index (SDI) regions bore the highest  age-standardized incidence rate（ASIR） and age-standardized prevalence rate(ASPR), while low SDI regions had the lowest. From 1990 to 2021, global ASIR and ASPR declined modestly (AAPC: -0.41% and -0.34%, respectively), while age-standardized mortality rate(ASMR) and ASDR fell more sharply (-2.22% and -0.85%). Projections to 2050 indicate a rising ASIR (12.83) and ASPR (227.60), with a persistent and pronounced female predominance and increasing uncertainty in long-term estimates.

RA remains a substantial global public health challenge, marked by significant geographic and gender disparities. While mortality has improved, the rising prevalence and persistent disability burden necessitate enhanced, sex-specific prevention strategies and healthcare planning, particularly in light of aging populations.