Wegener's granulomatosis is an uncommon disease, in which the blood vessels are inflamed (vasculitis). This inflammation damages important organs of the body by limiting blood flow to those organs and destroying normal tissue.

Although the disease can involve any organ system, Wegener's granulomatosis mainly affects the respiratory tract (sinuses, nose, trachea, windpipe, lungs, and kidneys). This disorder can affect people at any age and strikes men and women equally. It is rare in African Americans compared with Caucasians.