What Is It?
Vasculitis means inflammation of blood vessels. The inflammation can be short term (acute) or long term (chronic), and it can be so severe that it reduces blood flow to tissues and organs. This can cause dangerous organ and tissue damage, especially when vasculitis affects blood vessels in the brain, lungs, kidneys or other vital areas.
Although the cause of most forms of vasculitis remains unknown, many forms probably are related to a problem with the immune system. One theory is that, for unknown causes, the immune system attacks the blood vessels, which causes them to become inflamed. Some researchers think this immune attack might be triggered by an infection, drug or something else in the environment.