Arteriovenous fistula

An arteriovenous (AV) fistula is an abnormal connection between an artery and a vein. Normally, blood flows from your arteries to your capillaries to your veins. Nutrients and oxygen in your blood travel from your capillaries to tissues in your body.

With an arteriovenous fistula, blood flows directly from an artery into a vein, bypassing some capillaries. When this happens, tissues below the bypassed capillaries receive less blood supply.

Arteriovenous fistulas usually occur in the legs, but can develop anywhere in the body. Arteriovenous fistulas are often surgically created for use in dialysis in people with severe kidney disease.

A large untreated arteriovenous fistula can lead to serious complications. If you've had an arteriovenous fistula created for dialysis, your doctors will monitor you for complications.

Symptoms Causes Complications

Small arteriovenous fistulas in your legs, arms, lungs, kidneys or brain often won't have any symptoms and usually don't need treatment other than monitoring by your doctor. Larger arteriovenous fistulas may cause symptoms.

Arteriovenous fistula symptoms may include:

  • Swelling and reddish appearance on the skin surface
  • Purplish, bulging veins that you can see through your skin, similar to varicose veins
  • Swelling in the arms or legs
  • Decreased blood pressure
  • Fatigue
  • Heart failure

An arteriovenous fistula in your lungs (pulmonary arteriovenous fistula) is a serious condition and can cause:

  • Difficulty breathing, especially when exercising
  • Blueness of the skin
  • Clubbing of fingers
  • Stroke

When to see a doctor

If you have any of these signs and symptoms, and think you might have an arteriovenous fistula, make an appointment to see your doctor. Early detection of an arteriovenous fistula may make your condition easier to treat and may reduce your risk of developing complications, such as blood clots or, in severe cases, heart failure.

© 1998-2015 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. Terms of use