Vasculitis

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Medical Author:

Siamak T. Nabili, MD, MPH

Siamak T. Nabili, MD, MPH

Dr. Nabili received his undergraduate degree from the University of California, San Diego (UCSD), majoring in chemistry and biochemistry. He then completed his graduate degree at the University of California, Los Angeles (UCLA). His graduate training included a specialized fellowship in public health where his research focused on environmental health and health-care delivery and management.

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Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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• Vasculitis Overview
• Vasculitis Causes and Types
• Vasculitis Symptoms
• When to Seek Medical Care
• Exams and Tests
• Vasculitis Treatment
• Self Care at Home
• Medical Treatment
• Medications
• Next Steps
• Follow-up
• Prevention
• Outlook
• Synonyms and Keywords
• Author and Editor
• Read more on Vasculitis from Healthwise
• Viewer Comments: Vasculitis - Describe Your Experience

Vasculitis Overview

The vascular system refers to the collection of all blood vessels in the body. Vasculitis is the term used for a group of diseases characterized by the inflammation of and damage to the blood vessels or the blood vessel walls. Vasculitis (plural vasculitides) can be a primary disease or a secondary condition related to another underlying disease.

Different types of vasculitis have certain patterns of distribution that may affect particular organs, certain types of vessels, or specific vessel sizes. Vasculitis diseases affecting arteries are sometimes called arteritis, and those involving the veins are sometimes called venulitis. Overall, vasculitides (all types of vasculitis or vasculitic disorders) are uncommon conditions.

In general terms, blood vessels can be divided into arteries, veins, and capillaries.

1. Arteries are the blood vessels carrying oxygenated blood from the lungs away from the heart to different organs.
   
   
2. Veins are blood vessels collecting the blood without oxygen from the body organs to carry back to heart to be pumped to the lungs where it receives oxygen.
   
   
3. The largest artery is the aorta coming out of the left side of the heart. The aorta divides into many smaller branches as it passes through the body, thus giving rise to arteries of different sizes. The small arteries (arterioles) then branch further into capillaries, which are very small blood vessels distributed diffusely within all organs of the body. The exchange of oxygen and waste products between the blood vessels and tissues happens at the level of the capillaries. These small blood vessels then coalesce to form small veins (venules) which give rise to larger and larger veins that eventually end up in the right side of the heart via the body's largest vein, the vena cava.