After suffering from vasculitis for years, actor and director Harold Ramis died of the disease yesterday (Feb. 24) at his Chicago-area home.

The term vasculitis describes a group of diseases that cause inflammation of the blood vessels. The inflammation, in turn, causes a decrease in the flow of blood to tissues and organs throughout the body. Vasculitis often targets certain parts of the body such as the lungs, kidneys or skin, according to the American College of Rheumatology.

There are several types of vasculitis. Autoimmune inflammatory vasculitis (the type that Ramis had) is a rare condition in which the immune system attacks the blood vessels. Ramis contracted the disease following a severe infection in May 2010, after which he had to relearn how to walk, according to the Chicago Tribune. [10 Celebrities with Chronic Illnesses]

Other types of vasculitis can be caused by allergic reactions, cancers, immune system disorders or certain drugs. The symptoms and treatments associated with vasculitis vary depending on the type of disease, the body parts affected and the severity of the illness.

Vasculitis affects both men and women, and symptoms of the disease can appear at any age. Kawasaki disease, for example, is a type of vasculitis that appears exclusively in children. It affects the coronary arteries, which carry blood to the heart. In most cases, children recover from Kawasaki disease within a few weeks.

A form of vasculitis called giant cell arteritis (GCA) occurs only in people older than 50 years of age. GCA affects medium and large blood vessels, especially the arteries that carry blood to the head, arms and legs, according to the Rare Diseases Clinical Research Network.

Doctors can diagnose vasculitis by a physical examination, a biopsy of affected tissue, a blood test or an angiography (an imaging technique that exposes blood vessel abnormalities).

Treatments for vasculitis may include glucocorticoids such as prednisone, a type of steroid medication that helps to reduce inflammation. In many cases of vasculitis, immune-suppressing drugs such as cyclophosphamide, methotrexate or azathioprine may be prescribed.

Because vasculitis can cause organ or tissue damage, some patients may need surgery, particularly if a blood vessel is blocked or if an organ (such as a kidney) is damaged.

The outlook for people with vasculitis is generally good, depending on the type of vasculitis they have and its severity. The condition can go into remission permanently or for long periods, only to reappear later in life. Early detection of vasculitis can be key to proper treatment.

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