Can Flying And Blood Clots Pose A Deadly Risk?

Over 300 million people travel on long-distance flights, which last more than four hours, each year. In such long-haul flights, passengers are mostly seated in the same position for hours together, except for a few minutes when they visit the restroom. Remaining in the same seated position in a crammed space, especially in the economy class, can spell danger for many travelers. This is why it is also commonly referred to as “economy class syndrome”.1

Not just a plane, anyone traveling for more than four hours, whether by air, car, bus, or train, can be at risk for blood clots. Blood clots, also called deep vein thrombosis (DVT), can be a serious risk for some long-distance travelers.2


How Can A Blood Clot Be Fatal?

A blood clot that moves from your legs to your lungs can be fatal

Blood clots can occur in the deep veins of your legs during long periods of travel. These veins are located below the surface and are not visible through the skin. The reason for the clot is simple – sitting still in a confined space for a long time. The longer you remain immobile, the greater is your risk of developing a blood clot. Usually, the blood clot will dissolve on its own. However, sometimes a serious health problem can occur when a part of the blood clot breaks off and travels to the lungs and causes a blockage. This is called a pulmonary embolism (PE), and it can be fatal.3


Flights lasting 8-10 hours or longer pose the greatest risk. DVT and PE are collectively known as venous thromboembolism.4 The good news is thromboembolism is preventable and simple methods can help you to protect your health and reduce your risk of blood clots during a long-distance journey.5

What Increases Your Risk For Blood Clots?

Age and obesity are some factors that can cause a blood clot


The risk of developing a blood clot is generally very rare even if you travel a long distance. The level of risk depends on the travel duration and whether you have any other risks for blood clots. Most people who develop travel-associated blood clots have one or more other risks for blood clots like,6

  • Age (risk increases after age 40)
  • Obesity (BMI greater than 30kg/m2)
  • Recent surgery or injury (within 3 months)
  • Use of estrogen-containing contraceptives
  • Hormone replacement therapy (hormones given to reduce menopause effects)
  • Pregnancy and the postpartum period (up to 6 weeks after childbirth)
  • Previous blood clot or a family history of blood clots
  • Active cancer or recent cancer treatment
  • Limited mobility
  • Catheter placed in a large vein
  • Varicose veins

The American College of Chest Physicians’ (CCP) guidelines debunked a myth that simply flying in economy class could put you at more risk for developing a blood clot. While researchers found no compelling evidence for this myth, they cautioned that being immobile for long periods anywhere is a risk factor.7


When people with one or more of the conditions mentioned above travel long-distance, the chances of developing a blood clot is greater. The more risks you have, the greater your chances of experiencing a blood clot. Talk to your doctor before you embark on a long journey. The most important thing is to learn and recognize the symptoms of blood clots.

Common Symptoms

Deep Vein Thrombosis (DVT)


50% of people with DVT show no symptoms at all. The most common symptoms of DVT that usually occur in the leg or arm are:

  • Swelling of your leg or arm
  • Pain or tenderness
  • Skin that is warm to the touch
  • Redness of the skin

Pulmonary Embolism (PE)


You can have a Pulmonary Embolism without any symptoms of a DVT. Symptoms of a PE include:

  • Difficulty in breathing
  • Increased heart rate than normal or irregular heartbeat
  • Chest pain or discomfort, which usually worsens with a deep breath or coughing
  • Anxiety
  • Coughing up blood
  • Lightheadedness, or fainting

If you experience any of these symptoms, seek medical help immediately.


How To Prevent Blood Clots During Travel?

Have enough leg room by stowing away your cabin baggage

Some simple steps can help you avoid developing a blood clot while flying.

  • Move or stretch your arms and legs or walk around the plane at regular intervals and changing positions in your seat.
  • Drink sufficient quantities of fluids at frequent intervals.
  • Wear loose-fitting clothes that do not restrict blood flow and make body movement easier.
  • Avoid alcoholic beverages before traveling and during travel.
  • Stow your baggage in a place that allows enough leg room.
  • Try not to cross your legs.
  • Wear compression stockings (Some experts warn against wearing commercial compression stockings. They are effective only if custom fit; if not, they may block blood flow.)
  • People on blood thinners, also known as anticoagulants, must follow your doctor’s recommendations on medication use.