How to Prevent Blood Clots on Flights (and Other Travel)

When traveling to a distant destination, whether it be by plane, car, bus, or train, sitting for prolonged periods in cramped spaces is pretty much a given. And while you may have considered what snacks to pack and what movies to load on your phone, you may not have given much thought to an important health consideration: how to prevent blood clots when traveling.

Why do flights cause blood clots?

According to the American Society of Hematology, sitting immobile in a confined space with little leg room during long flights and other lengthy travel can cause blood clots to develop in the large, deep veins (those below the surface that are not visible through the skin), a condition known as deep vein thrombosis (DVT). The risk of clot formation increases on long trips largely due to reduced leg movement. This limited activity lessens muscle contractions in the legs, which are essential for maintaining good blood circulation. As a result, slower blood flow occurs, heightening the risk of clots developing. 

And on planes, in particular, changes in air pressure and reduced oxygen levels in the cabin can also contribute to an increased risk of clots. The longer the flight (or other mode of travel), the higher the risk for developing a clot, with flights of 8 to 10 hours or longer posing the highest risk. 

Many times a blood clot will dissolve on its own, says the U.S. Centers for Disease Control and Prevention (CDC). However, in some cases, a part of the clot can break off and travel to the lungs causing a blockage. Known as a pulmonary embolism (PE), this situation can be fatal — according to the CDC, an estimated 60,000 to 100,000 Americans die each year from DVT/PE.

Who is at risk of DVT?

A variety of factors can put a person at increased risk for developing DVT. In addition to sitting for prolonged periods of time without getting up and walking around, according to the CDC and American Society of Hematology, these factors include:

• Having had a previous blood clot
• A family history of blood clots
• A known clotting disorder
• Recent surgery, hospitalization, or injury
• Use of estrogen-containing birth control or hormone-replacement therapy
• Current or recent pregnancy
• Older age (the risk is increased for people over 60)
• Obesity
• Cancer or cancer treatments such as chemotherapy
• Serious medical conditions such as congestive heart failure (CHF) or inflammatory bowel disease (IBD)
• Smoking
• Trauma
• Chronic inflammatory diseases
• Diabetes
• High blood pressure
• High cholesterol
• Prior central line placement

Symptoms of DVT

Sometimes there aren’t any noticeable symptoms of DVT, according to the Mayo Clinic. When symptoms are present, they may include:

• Leg swelling
• Pain or discomfort in the leg, frequently beginning in the calf area
• Altered skin color on the affected leg, which may appear red or purple
• Sensation of warmth in the leg that is impacted

According to the Cleveland Clinic, symptoms of a pulmonary embolism include:

• Chest pain
• Shortness of breath
• Cough with blood
• Lightheadedness
• Fainting

Seek medical attention right away if you develop any of the symptoms of DVT or a pulmonary embolism.

Pre-travel preparations

Fortunately, there are steps you can take to reduce your risk of developing blood clots during long-distance travel.

Be sure to make an appointment with your healthcare provider to take place at least a month before your trip. In addition to keeping you up to date on any vaccines that may be recommended for your destination, they can go over any special precautions you may need to take to help avoid blood clots on your travels. Let your doctor know if you think you may be at increased risk of clots.

Before and during your flight (or other method of transportation), it is important to stay hydrated by consuming adequate fluids. According to the U.S. National Academies of Sciences, Engineering, and Medicine, this is about 15.5 cups (3.7 liters) of fluids each day for men and 11.5 cups (2.7 liters) of fluids each day for women from both food and beverages. Before and during travel, avoid alcohol and caffeine (both of which can contribute to dehydration), notes the Willis-Knighton Health System, as well as salty snacks. Also avoid sleeping pills or other tranquilizers, which could discourage you from moving. Additionally, make sure you take any medications you should be taking, such as any blood thinner you may have been prescribed if you are at high risk for clots.

In-flight strategies to prevent blood clots

Once you’re in the air (or on the road or rails), there are a variety of strategies you can use to help keep your blood pumping and reduce your risk of DVT. 

First off, according to RWJBarnabas Health, you should wear loose clothing and comfortable shoes. In consultation with your doctor, you may also want to consider using graduated compression stockings, which apply pressure to the lower legs, helping to reduce swelling and maintain blood flow.

Make a point to get some movement by walking around every two to three hours and changing position in your seat. Whenever possible, choose an aisle seat so that you can easily get up and move around. If you’re traveling by car, experts recommend stopping for at least 15 minutes roughly every two hours. 

While you’re seated, exercise your calf muscles by stretching your legs and doing seated leg exercises. The CDC recommends the following:

• Raise and lower your heels while keeping your toes on the floor.
• Raise and lower your toes while keeping your heels on the floor.
• Tighten and release your leg muscles.

Also, store your luggage overhead so that you have the maximum amount of legroom possible, and do not sit with your legs crossed.

Post-travel care

Once you’re at your destination, it’s important to continue monitoring for symptoms of DVT and pulmonary embolism for about a week or two and to call your doctor or go to the emergency room right away if you are showing any signs of either condition. 

Miles high, risk low

While traveling, and especially on long flights, it’s essential to be mindful of your health and take proactive steps to prevent blood clots. DVT may not always be at the forefront of our minds when planning a trip, but it’s a serious condition that can be mitigated with simple, thoughtful actions. Remember, the key to a successful and enjoyable journey lies not just in the destination but also in ensuring a safe and healthy travel experience.

Disclaimer of Medical Advice: This information does not constitute medical advice or recommendation of any kind, and you should not rely on any information contained in such posts or comments to replace consultations with your qualified healthcare professionals to meet your individual needs.