What is vasculitis? Vasculitis is an inflammation of the blood vessels that typically has some immune system-related cause. This video covers the pathophysiology of vasculitis in general, as well as more specific conditions like giant cell arteritis, Takayasu arteritis, Kawasaki disease, polyarteritis nodosa, Buerger disease, granulomatosis with polyangiitis, microscopic polyangiitis, and Churg-Strauss syndrome, as well as the different signs and symptoms between them.