What Is Vasculitis?

Vasculitis is an inflammation of the blood vessels in the body. In vasculitis, the body’s immune system mistakenly attacks the body’s own blood vessels, causing them to become inflamed. Inflammation can damage the blood vessels and lead to a number of serious complications.

Vasculitis can affect any of the body’s blood vessels. These include arteries, veins, and capillaries. Arteries are vessels that carry blood from the heart to the body’s organs, veins are the vessels that carry blood back to the heart, and capillaries are the tiny blood vessels that connect the small arteries and veins.

When a blood vessel becomes inflamed, it can:

• Narrow, making it more difficult for blood to get through
• Close off completely so that blood can’t get through at all (occlusion)
• In rare cases, stretch and weaken so much that it bulges (aneurysm) and may possibly burst (aneurysm rupture)

Figure A shows a normal artery with normal blood flow (the inset image shows a cross-section of the normal artery). Figure B shows an artery narrowed due to inflammation in the arterial wall, causing decreased blood flow (the inset image shows a cross-section of the inflamed artery). Figure C shows a totally occluded (blocked) artery due to inflammation and scarring in the arterial wall (the inset image shows a cross-section of the block artery). Figure D shows an artery containing an aneurysm.

The disruption in blood flow from inflammation can damage the body’s organs. Specific signs and symptoms depend on which organ has been damaged and the extent of the damage. Typical signs and symptoms of inflammation (fever, swelling, and a general sense of feeling ill) are common among people with vasculitis.

Outlook

The outlook for people who have vasculitis varies depending on both the type and severity of the vasculitis. The course of a case of vasculitis can be hard to predict. Treatment is often very effective if vasculitis is diagnosed and treated early. Vasculitis may disappear or go into a period of remission. In some cases, it may be a chronic problem, requiring ongoing treatment, or it may come back (“flare”) after a period of remission. In more severe cases, treatment may not help, and vasculitis can lead to disability or even death.

Much is still unknown about vasculitis. There are many different types of vasculitis, but overall it is a fairly rare condition in the general population. Additional research is needed to learn more about the various types of vasculitis and their causes, treatments, and remission patterns.