Vasculitis is a general term for a group of uncommon diseases that feature inflammation in the body’s blood vessels. The body’s blood vessels are referred to as the vascular system. The blood vessels are comprised of the arteries that pass oxygen-rich blood to the tissues of the body and veins that return oxygen-depleted blood from the tissues to the lungs for oxygen. Vasculitis is characterized by inflammation in and damage to the walls of the different blood vessels.
Each and everyone of the vasculitis disease is defined by certain patterns of distribution of blood vessel involvement, especially in organ involvement and laboratory test abnormalities. As a group, these diseases are referred to as vasculitides.