Medically Reviewed by Jennifer Robinson, MD on September 20, 2023
4 min read

Vasculitis is a general term that refers to inflammation of blood vessels. Vasculitis can affect very small blood vessels (capillaries), medium-sized blood vessels (arterioles and venules), or large blood vessels (arteries and veins). If blood flow in a vessel with vasculitis is reduced or stopped, the tissues that receive blood from that vessel begin to die.

Some of the many forms of vasculitis may be restricted to particular organs. Examples include vasculitis that affects only the skin, eye, brain, or certain internal organs. There are also types of vasculitis that may affect many organ systems at the same time. Some of these generalized forms may be quite mild and may not require treatment. Others may be severe, affecting critical organs.

In most cases, the cause of vasculitis is unknown; however, it is clear that the immune system (the system that keeps the body healthy) plays a role. While the immune system usually works to protect the body, it can sometimes become overactive, attacking parts of the body. Sometimes an allergic reaction to certain medicines can trigger the immune system to go awry. In other cases, the origins may be traced to recent or ongoing infections, such as those caused by certain viruses.

Vasculitis also may be related to other diseases of the immune system that the person has had for months or years. For example, it could be a complication of rheumatoid arthritis, lupus or Sjogren's syndrome.

Vasculitis can be very serious. In an extreme situation, when a segment of a blood vessel becomes weakened, it may then stretch and bulge (called an aneurysm). The wall of the blood vessel can become so weak that it ruptures and bleeds, possibly causing death. Fortunately, this is a very rare event.

If a blood vessel becomes inflamed and narrowed, the blood supply to the area of the body it serves may be partially or completely blocked. If alternate blood vessels (called collateral blood vessels) are not available in sufficient quantity to carry the blood to such sites, the tissue supplied by the affected vessels will die.

An enormous number of vasculitis symptoms are possible because any organ system may be involved. If the skin is involved, there may be a rash. If nerves lose blood supply, there may initially be an abnormal sensation followed by a loss of sensation.

Vasculitis in the brain may cause a stroke or, in the heart, may result in a heart attack. Inflammation in the kidney could result in abnormalities noted on urine tests and can lead to progressive kidney failure.

Sometimes, the symptoms may be as general as fever, loss of appetite, weight loss, and loss of energy. If you notice any unusual symptoms, see your doctor.

The diagnosis of vasculitis is based on your medical history, symptoms, a physical exam, and the results of specialized lab tests. A doctor can test for blood problems that can go along with vasculitis. These include:

Blood tests also can spot immune complexes or antibodies (ways the body fights off what it thinks is a threat) that cause vasculitis. Other tests may include X-rays of blood vessel, tissue biopsies, and heart scans.

Treatment for vasculitis depends on your diagnosis and the affected organs. If the cause is an allergic reaction, it may go away on its own. In other instances, when critical organs such as the lungs, brain, or kidneys are involved, you’ll need aggressive and timely treatment.

Treatment generally consists of corticosteroid medications (steroids). Chemotherapeutic drugs, which include those used to treat cancer, such as methotrexate, are also used, but in doses considerably lower than people with cancer may receive. The goal of this type of chemotherapy is to weaken the abnormal immune response that has led to blood vessel damage.

Other medications, such as biologics, may treat some conditions that cause vasculitis.

The outlook depends on the type of vasculitis. In the past, people with severe vasculitis may have expected to survive only weeks or months. Today, regular life spans are possible with proper treatment. The success of treatment is related to prompt diagnosis, aggressive treatment, and careful follow-up.

Once vasculitis is under control, you may slowly stop medications, with hope for a long remission or cure. Because doctors can’t predict how long you may remain in remission, it’s very important for people with more severe forms of vasculitis to continue under the care of a doctor who specializes in rheumatology for the rest of their lives.