Vasculitis explained: types, symptoms and treatment

What vasculitis is

Vasculitis means inflammation of the blood vessels — the arteries, veins and tiny capillaries that carry blood around the body. When a vessel wall becomes inflamed, it can swell and narrow, reducing blood flow to the tissue it supplies, or it can weaken and, rarely, balloon or bleed. Because blood vessels are everywhere, the effects depend entirely on which vessels are involved and where. Most types of vasculitis are thought to be autoimmune, meaning the immune system, which normally fights infection, mistakenly attacks the body's own vessels. Some are linked to infections, medicines or other conditions. Vasculitis is generally not contagious and, in most forms, not inherited. It ranges from a mild rash that settles on its own to serious disease that threatens organs, which is why getting the right diagnosis matters.

The many types and their symptoms

There are many kinds of vasculitis, often grouped by the size of vessel they affect. Some affect large arteries, such as giant cell arteritis, which typically causes new headaches, scalp tenderness and jaw ache in older people and can threaten sight. Others affect medium or small vessels and can involve the skin, nerves, kidneys, lungs, sinuses and gut. Common general symptoms across many types include tiredness, fever, weight loss, aching joints and muscles, and feeling unwell. More specific signs depend on the site: a raised purple skin rash, numbness or weakness from nerve involvement, blood in the urine or kidney problems, breathlessness or coughing up blood from the lungs, and sinus or ear trouble. Because these features overlap with many other illnesses, vasculitis can be hard to spot, and a high level of suspicion is often needed.

When it is urgent

Some forms of vasculitis are medical emergencies because they can cause permanent damage quickly. Giant cell arteritis is one: new severe headache, tenderness of the scalp or temples, pain in the jaw when chewing, and especially any visual disturbance or sudden loss of vision in an older person need urgent same-day assessment, because prompt treatment can prevent blindness. Vasculitis affecting the kidneys or lungs can also worsen rapidly, so blood in the urine, marked breathlessness or coughing up blood need urgent care. Signs that any severe illness is developing — such as feeling very unwell, confusion or collapse — always warrant emergency help. The general rule is that rapidly progressing symptoms, loss of vision, or involvement of vital organs should never be left, as early treatment often makes the difference between recovery and lasting harm.

How it is diagnosed

Diagnosing vasculitis usually involves piecing together the pattern of symptoms with a range of tests, often led by a specialist. Blood tests look for inflammation and for particular antibodies linked to certain types of vasculitis, and check how the kidneys and other organs are working. Urine tests can reveal hidden kidney involvement. Depending on the suspected type, a biopsy — taking a small sample of affected tissue such as skin, an artery or kidney — can confirm inflammation of the vessels under the microscope. Scans, including specialised imaging of the arteries, help show which vessels are affected. Because vasculitis mimics infections and other conditions, doctors also work to rule these out. Building this picture allows the team to identify the specific type, judge how active and severe it is, and plan the right treatment.

How it is treated and monitored

Treatment depends on the type and severity of vasculitis, but the aim is to switch off the inflammation, protect organs and then keep the condition under control. For active, serious disease, medicines that calm or suppress the immune system are the mainstay, often a steroid to bring inflammation down quickly alongside other immune-suppressing treatments to control it and allow steroids to be reduced. Milder forms may need less intensive treatment. Once the disease is under control, treatment usually continues at a lower level to prevent flares, and is reviewed regularly. Because both the condition and its treatments carry risks, ongoing monitoring is important, including watching for organ involvement, side effects and infection. Care is often shared between specialists and the GP. With modern treatment, many people with vasculitis achieve good control, though it can be a long-term condition that needs continued attention.