People have an increased risk of developing a blood clot when traveling long distances. In combination with other risk factors, sitting for a long period can make a blood clot more likely to form.

A blood clot can become dangerous if it breaks free and blocks blood flow to the lungs. If a person has a history of blood clots or knows that they are at increased risk of a blood clot, they should talk to their doctor before traveling long distances by plane, car, or bus.

Keep reading for more information on what blood clots are, how to prevent them, and how to travel by plane safely with an existing clot.

A woman stands with a suitcase at the airport and thinks about the risks with a blood clot and flying.Share on Pinterest
Due to sitting for a long time, flying can increase the risk of developing a blood clot.

A blood clot, also called a thrombus, is a semi-solid mass of blood that forms in a vein or artery. Blood clots may be stationary and block blood flow, or they may be loose and travel to different parts of the body where blockages can occur.

When traveling long distances, people may be concerned about a type of blood clot known as a deep vein thrombosis (DVT). DVT typically occurs in one of the legs, but it can affect either one of the arms as well. People who are sitting for extended periods during travel are at a higher risk of developing a DVT.

In some cases, a portion of a clot may break free, which is known as an embolism. An embolism can travel to different parts of the body, including the lungs, brain, or heart.

Doctors refer to an embolism inside an artery to the lungs as a pulmonary embolism (PE). Without prompt treatment, a PE can be life threatening.

A doctor can treat both DVT and PE simultaneously. In many cases, they can use medication that helps thin the blood. Some people may need to take a blood thinning medication on a long-term basis to prevent future clots from forming.

According to the Centers for Disease Control and Prevention (CDC), anyone can develop DVT during a long flight or when traveling long distances in a car, train, or bus.

Other risk factors for developing DVT include:

  • slow blood flow due to limited movement or sitting for long periods
  • injury to a vein due to muscle injury, a fracture, or surgery
  • chronic medical conditions, such as:
  • increased estrogen due to hormonal birth control, pregnancy, or hormone therapy
  • family history of DVT
  • previous DVT
  • obesity
  • natural aging
  • genetic factors

Not everyone with DVT will develop symptoms. As DVT can develop during travel, a person should be aware of some of the potential signs and symptoms. Symptoms to look out for include:

  • pain or tenderness with no explanation
  • swelling of the leg or arm
  • redness on the skin
  • skin that is warm to the touch

If a piece of a DVT has broken free and traveled to either one of the lungs, it is a PE.

According to the CDC, the symptoms of a PE include:

  • faster-than-normal heart rate
  • trouble breathing
  • coughing up blood
  • anxiety
  • lightheadedness
  • chest pain that worsens with deep breathing or coughing

Traveling for 4 or more hours by plane, car, train, or bus increases the risk of developing DVT, due to the person spending long periods sitting.

People traveling by car should take regular rest stops on long trips. Those traveling by bus or train should get up and stretch when the bus or train makes a longer stop.

When traveling by plane, it is not always easy to walk around. The CDC recommend:

  • wearing compression socks
  • standing and stretching every few hours
  • watching for symptoms of DVT
  • exercising the calf muscles while sitting to promote blood flow
  • continuing using blood thinners as a doctor has prescribed, if relevant
  • talking to a doctor about other preventive steps based on the person’s unique needs

In addition, a person should take steps to stay hydrated during flights and other trips. Drinking plenty of water and avoiding alcoholic beverages are advisable.

A person should avoid flying if they have a newly diagnosed DVT due to the risk of related complications during travel, such as part of it breaking free. Healthcare professionals recommend waiting up to 4 weeks from the start of treatment for DVT before traveling.

If a person with DVT has to fly, they should talk to their doctor about their risk. They should also continue taking any prescribed blood thinning medication.

A previous history of DVT or PE puts a person at higher risk for DVT while flying. A person should discuss their risk with a doctor to determine whether they can take any steps to help prevent DVT from occurring during their flight.

A person should seek emergency medical care if they experience any symptoms of PE. No one should travel with an untreated PE.

If a person experiences symptoms of a PE during a flight, they should let the flight crew know. An emergency landing may be necessary so that the person can get appropriate medical care.

DVT is a clot that often develops in the legs but may occur in the arms.

DVT is not usually very dangerous, but if a portion of the clot breaks free, it can travel to the lungs and become a PE.

If this occurs, more severe symptoms will likely ensue, and a person will need to seek emergency medical treatment.

A person who remains sedentary while traveling for longer than 4 hours has a higher risk of developing DVT, particularly if they have other risk factors.

It is essential to speak with a doctor before traveling with a DVT or PE.