Often, swollen ankles while flying is harmless and goes away on its own. In rare cases, ankle swelling may be a sign of deep vein thrombosis (DVT), which is more serious and requires medical treatment.

Swollen ankles are a common side effect of long-haul flights. They most often occur due to the buildup of fluid in the legs, known as edema.

Studies show that edema is present in around 97 in 100 people who fly for more than 7 hours. In some other cases, a person’s ankles may swell due to DVT.

In this article, we discuss the causes of swollen ankles while flying. We also outline other symptoms and provide possible prevention tips to consider before and during flying.

A person walking through an airport. Swollen ankles from flying are a common condition.Share on Pinterest
DuKai photographer/Getty Images

Swollen ankles during and after air travel may result from conditions such as a buildup of fluid and blood clots.

We discuss these causes in more detail below.

Leg edema

Often, a person develops swollen ankles while flying due to swelling (edema) in the lower leg. This is the term for a buildup of fluid in the body, which in this instance occurs in the legs.

Leg edema from flying is very common and is often harmless. The most common cause of edema in the lower leg while flying is inactivity and restricted movement.

Learn more about the causes of swollen ankles here.


Venous thromboembolism (VTE) is a disease that occurs when blood clots form in the veins. DVT is a form of VTE. It is the term for blood clots that form in a person’s deep veins.

Flying can cause DVT to occur in the legs. This condition can also cause edema and for a person’s ankles to swell.

Factors that can cause DVT during flying include:

  • lower limb immobility due to sitting for extended periods
  • slow blood flow (venous stasis) through the veins in the legs due to inactivity
  • reduced blood flow to the deep and superficial veins of the legs

Learn more about deep vein thrombosis here.

The symptoms of swollen ankles from flying may depend on the underlying condition causing it.

Leg edema symptoms

If a person has swollen ankles due to leg edema, they may experience the following symptoms:

  • the leg starts to feel full or heavy
  • the leg starts to look swollen
  • when the person presses the swelling, it leaves a dent
  • clothing or jewelry starts to feel tight and uncomfortable
  • the skin near the swelling feels tight or warm
  • it becomes more difficult to move the foot
  • there is a sensation of tautness and sometimes pain in the surrounding area

DVT symptoms

Swollen ankles may also occur while flying due to DVT. Common symptoms of DVT include:

  • swelling of the leg
  • pain or tenderness around the affected area
  • skin that is warm to the touch
  • redness of the skin around the ankle

Learn more about the symptoms of deep vein thrombosis here.

If a person has symptoms of DVT, they should speak with a doctor.

A pulmonary embolism (PE) is a serious complication of DVT. This happens when a part of the blood clot breaks off and travels through the bloodstream to a person’s lungs.

This can cause a blockage in the blood vessels present in the lungs. This blockage is a PE.

If the clot is small, a person can recover with appropriate treatment. However, if the clot is large, it can stop blood from reaching the lungs, which can be fatal.

A person can develop PE even without any symptoms of DVT. Symptoms of a PE include:

A person should seek immediate medical help if they experience these symptoms.

If a person is worried about DVT while flying, they should speak to a healthcare professional. They can then understand which signs and symptoms to look out for.

Those who may be at higher risk of DVT when flying include people:

A person can reduce their risk of swollen ankles and DVT by wearing graduated compression stockings while flying.

These stockings work to improve blood flow in the legs during flying. They exert the greatest degree of compression at the ankle. The level of compression gradually decreases up the garment.

There are a number of steps a person can take to decrease their risk of edema and DVT while flying. These include:

  1. Move the legs frequently when on long flights by walking up and down the cabin.
  2. Exercise the calf muscles to improve the flow of blood.
  3. Avoid sitting down for too long a period of time.
  4. If a person has been sitting for a long time, they should take a deep breath and stretch their legs.
  5. A person can periodically extend their legs straight out and flex the ankles, pulling the toes towards the body.
  6. They can also pull each knee up toward the chest and hold it there for 15 seconds, repeating this up to 10 times.

Learn more about tips for healthy flying here.

Here are some common questions about swollen ankles from flying.

How long do swollen ankles last after flying?

Swollen ankles due to flying often don’t last a long time and the swelling usually goes away on its own.

However, if the swelling persists and a person experiences ongoing symptoms of DVT, they should contact a healthcare professional.

When should I be concerned about swollen ankles?

If a person experiences symptoms of DVT, they should contact a healthcare professional because this condition can cause serious illness and in some cases be life threatening. DVT symptoms include:

  • swelling
  • pain
  • tenderness
  • redness of the skin

It is very common for a person’s ankles to swell during or after flying.

This is often due to a buildup of fluid known as edema. Swollen ankles due to edema are often harmless and the swelling usually goes away on its own.

In some other cases, swollen ankles may be a sign of DVT. This is a more serious condition that occurs when blood clots form in the deep veins, often in a person’s legs.

Other symptoms of DVT include pain, tenderness, and redness of the skin. A person should contact a healthcare professional if they experience symptoms of DVT or their ankle swelling does not go away after flying.

A person may also wish to wear graduated compression stockings and exercise their calf muscles while flying to help prevent swollen ankles.