Vasculitis means inflammation of a blood vessel. There are many different types of vasculitis and they are all caused by specialized immune cells, such as neutrophils, lymphocytes, eosinophils, and multinucleated giant cells. In vasculitis, the immune cells damage blood vessels and prevent them from functioning normally.
Blood vessels are hollow tubes that carry blood throughout the body. The open space in the centre is called the lumen and it is surrounded by the vessel wall. The inflammation in vasculitis damages the blood vessel wall, which causes the lumen of the blood vessel to decrease in size. As a result, less blood is able to flow through the blood vessel. This may cause injury to the organs or tissues that normally receive blood from that vessel.
Blood vessels are found throughout the body and they are divided into types depending on their size and whether they are delivering blood to the body, or bringing it back to the heart. Blood leaves the heart through a large blood vessel called the aorta. The aorta connects with arteries and arterioles (small vessels similar to arteries) to deliver blood to the body. Veins and venules (small vessels similar to veins) bring blood back to the heart. Arterioles and venules are connected by small blood vessels called capillaries, which allow oxygen, carbon dioxide, nutrients, and waste to flow between tissues and blood. Any of these blood vessels may be affected by vasculitis.
The following is a list of some of the more common types of vasculitis.
For more information about these conditions, please speak to your doctor.