Vasculitis Causes and Risk Factors

Vasculitis occurs when your immune system hurts your blood vessels by mistake. What causes this to happen is not fully known, but when it occurs, your blood vessels swell and can narrow or close off. Rarely, the blood vessel wall may weaken, causing it to expand or bulge. This bulge is known as an aneurysm.

**Effects of inflammation on an artery.** This series of images shows a normal artery (Figure A), a narrowed artery with inflammation (Figure B), a totally blocked (occluded) artery (Figure C), and an artery with abnormal blood flow from an aneurysm (Figure D).

What are the risk factors for vasculitis?

Age

Vasculitis can happen at any age. However, some types of vasculitis are more common among people of certain ages.

Buerger’s disease usually affects men younger than 45 who smoke or have smoked.
IgA vasculitis is diagnosed more often in children than adults.
Giant cell arteritis affects adults 50 years and older and is most common in people who are in their 70s and 80s.
Kawasaki disease affects only children and is most common under the age of 5.

Family history

These types of vasculitis may run in families.

Behçet’s disease
Granulomatosis with polyangiitis
Kawasaki disease

Lifestyle habits

Smoking raises your risk of vasculitis
Using illegal drugs, such as cocaine, also raises your risk.

Medicines

The risk of vasculitis is higher if you take certain medicines, including:

Hydralazine, used to treat high blood pressure
Levamisole, used for infections, but also added to most cocaine
Propylthiouracil, used to treat some thyroid disorders
Tumor necrosis factor inhibitors, a treatment for some immune diseases

Other medical conditions

Autoimmune disorders, such as lupus, rheumatoid arthritis, and scleroderma
Hepatitis B or C, infections that sometimes trigger vasculitis inflammation
Lymphoma, a cancer of the blood

Race or ethnicity

Behçet’s disease is most common in Turkey and is relatively common in other countries in the Mediterranean, the Middle East, Central Asia, China, and Japan. It is relatively uncommon in Northern and Western Europe and the United States.
Giant cell arteritis is most common in Scandinavia and Minnesota.
Kawasaki disease is more common among children of Japanese descent.

Sex

Behçet’s disease is more common in men in some countries and more common in women in other countries.
Buerger’s disease is more common in men.
Giant cell arteritis affects women 2 to 4 times more often than men.
Microscopic polyangiitis affects men slightly more often than women.

Can vasculitis be prevented?

Some types of vasculitis cannot be prevented, as they are caused by autoimmune disorders. However, depending on what caused the vasculitis, some types can be prevented from flaring up.

Medicines may be used to reduce the symptoms of vasculitis.

Anticlotting medicines treat blood clots or prevent blood clots from forming. You may need them if you have an aneurysm.
Beta blockers lower blood pressure. You may need them if you have an aneurysm.
Statins control or lower high blood cholesterol levels.

Healthy lifestyle changes may also be recommended.

Adopt a heart-healthy lifestyle.
Avoid illegal drugs, including cocaine. If you use illegal or street drugs, ask your provider how to get help to stop. You can also call the Substance Abuse and Mental Health Services Administration’s (SAMHSA) National Helpline at 1-800-662-HELP.
Quit smoking and tobacco. Visit Smoking and Your Heart and the National Heart, Lung, and Blood Institute’s Your Guide to a Healthy Heart. Although these resources focus on heart health, they include basic information about how to quit smoking. For free help and support to quit smoking, you may call the National Cancer Institute’s Smoking Quitline at 1-877-44U-QUIT (1-877-448-7848).