Inflammation in the body of a blood vessel or a lymph vessel (a tube that carries the clear liquid in the body that cleans tissues and helps to remove harmful bacteria from blood): "Vasculitis usually leads to damage of the linings of vessels, with a narrowing or blockage, so the blood flow is decreased or stopped."

"The various vasculitides that exist in people cause the tissues that are supplied by the affected vessels to be damaged, or destroyed, because of the lack of blood supply and oxygen."