The 2012 Revised International Chapel Hill Consensus Conference (CHCC) on the Nomenclature of Vasculitides aimed to update and expand the 1994 CHCC nomenclature, addressing advancements in understanding and changes in medical terminology. The 2012 CHCC introduced new terms such as granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, and IgA vasculitis, and included categories for variable vessel vasculitis and secondary forms of vasculitis. The conference defined large vessel vasculitis (LVV) as affecting the aorta and its major branches, medium vessel vasculitis (MVV) as affecting medium arteries, and small vessel vasculitis (SVV) as affecting small vessels. SVV was further divided into ANCA-associated vasculitis (AAV) and immune complex SVV. The conference also categorized vasculitides associated with systemic diseases or probable etiologies, emphasizing the importance of identifying primary causes in patients with vasculitis.The 2012 Revised International Chapel Hill Consensus Conference (CHCC) on the Nomenclature of Vasculitides aimed to update and expand the 1994 CHCC nomenclature, addressing advancements in understanding and changes in medical terminology. The 2012 CHCC introduced new terms such as granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, and IgA vasculitis, and included categories for variable vessel vasculitis and secondary forms of vasculitis. The conference defined large vessel vasculitis (LVV) as affecting the aorta and its major branches, medium vessel vasculitis (MVV) as affecting medium arteries, and small vessel vasculitis (SVV) as affecting small vessels. SVV was further divided into ANCA-associated vasculitis (AAV) and immune complex SVV. The conference also categorized vasculitides associated with systemic diseases or probable etiologies, emphasizing the importance of identifying primary causes in patients with vasculitis.