Pulmonary Arteriovenous Fistula: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor treats Pulmonary Arteriovenous Fistula?
A pulmonologist usually treats this condition, and embolization is often done by an interventional radiologist. Many patients also see a genetic specialist if HHT is the cause. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What it is
A pulmonary arteriovenous fistula is an abnormal connection between an artery and a vein inside the lung. Blood skips the tiny capillaries where it normally picks up oxygen and flows straight from the artery to the vein, so less oxygen gets into the bloodstream. The fistula also lets blood bypass the lung's natural filter, raising the risk that a clot or air bubble travels to the brain.
Symptoms
Many people have no symptoms at all. When symptoms appear, they often include shortness of breath during activity, tiredness, and sometimes coughing up blood, which needs medical attention right away. Doctors may also notice small red spots on the skin called telangiectasias, frequent nosebleeds, or enlarged, rounded fingertips called clubbing.
Causes and who gets it
The most common cause is hereditary hemorrhagic telangiectasia (HHT), a genetic condition that runs in families and causes abnormal blood vessels in the lungs, brain, skin, and digestive tract. Rarely, a fistula is present at birth without family history or acquired after injury, surgery, or infection.
How doctors diagnose it
Doctors often suspect the problem when a chest X-ray shows an unusual spot. The most useful test is a CT scan of the chest; a CT angiogram uses injected dye to show the blood vessels clearly. Doctors may also check oxygen with a finger clip.
Treatment
Not every fistula needs treatment. Small ones are often watched with repeat imaging. Larger or symptomatic fistulas are usually treated with embolization, in which a doctor threads a thin tube through a blood vessel and places tiny plugs or coils to block the abnormal connection. Some fistulas come back or need repeat procedures. People with HHT may need regular screening and antibiotics before dental work.
When to see a doctor
Anyone who coughs up blood should get medical care right away. Shortness of breath, chest pain, or sudden severe headache also need prompt attention, because a fistula can allow a clot to reach the brain and cause a stroke.
How a direct primary care or concierge doctor fits in
Either kind of doctor can order chest imaging, check oxygen levels, and manage related issues like frequent nosebleeds. When a fistula is suspected, they refer the patient to a specialist for testing and treatment, then handle follow-up and coordinate screening for HHT.
Common questions
Is a pulmonary arteriovenous fistula cancer?
No, it is not cancer. It is an abnormal blood vessel connection, and it does not spread the way cancer does.
Can it go away on its own?
Small fistulas sometimes stay the same size for years and cause no trouble. They rarely disappear without treatment, so doctors usually monitor them with repeat imaging.
Is treatment always needed?
No. Doctors often recommend treatment for larger fistulas or ones causing symptoms, because of the risk of clots traveling to the brain. The right choice depends on the size of the fistula and the person's overall health.
Can I exercise if I have one?
Many people with small, untreated fistulas can be active. However, some doctors advise avoiding heavy straining or diving. Ask your doctor what is safe for your specific situation.
Sources
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
