What Is Vasculitis?

Vasculitis (vas-kyu-LI-tis) is a condition that involves inflammation in the blood vessels. The condition occurs if your immune system attacks your blood vessels by mistake. This may happen as the result of an infection, a medicine, or another disease or condition.

“Inflammation” refers to the body’s response to injury, including injury to the blood vessels. Inflammation may involve pain, redness, warmth, swelling, and loss of function in the affected tissues.

In vasculitis, inflammation can lead to serious problems. Complications depend on which blood vessels, organs, or other body systems are affected.


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

If a blood vessel is inflamed, it can narrow or close off. This limits or prevents blood flow through the vessel. Rarely, the blood vessel will stretch and weaken, causing it to bulge. This bulge is known as an aneurysm (AN-u-rism).

inflammation_vasculitisFigure A shows a normal artery with normal blood flow. The inset image shows a cross-section of the normal artery. Figure B shows an inflamed, narrowed artery with decreased blood flow. The inset image shows a cross-section of the inflamed artery. Figure C shows an inflamed, blocked (occluded) artery and scarring on the artery wall. The inset image shows a cross-section of the blocked artery. Figure D shows an artery with an aneurysm. The inset image shows a cross-section of the artery with an aneurysm.

The disruption in blood flow caused by inflammation can damage the body’s organs. Signs and symptoms depend on which organs have been damaged and the extent of the damage.

Typical symptoms of inflammation, such as fever and general aches and pains, are common among people who have vasculitis.


There are many types of vasculitis, but overall the condition is rare. If you have vasculitis, the outlook depends on:

  • The type of vasculitis you have
  • Which organs are affected
  • How quickly the condition worsens
  • The severity of the condition
  • Treatment often works well if it’s started early. In some cases, vasculitis may go into remission. “Remission” means the condition isn’t active, but it can come back, or “flare,” at any time.

Sometimes vasculitis is chronic (ongoing) and never goes into remission. Long-term treatment with medicines often can control the signs and symptoms of chronic vasculitis.  Rarely, vasculitis doesn’t respond well to treatment. This can lead to disability and even death.

Much is still unknown about vasculitis. However, researchers continue to learn more about the condition and its various types, causes, and treatments.

immune complex

Source:  National Heart Lung and Blood Institute, What Is Vasculitis?  September 23, 2014

Vasculitis (En Español) 

Click here to download the Vasculitis brochure

Key Resources: