Blood Clots and Travel

Long-haul flights are an integral part of international travel offering the convenience of crossing continents within hours. However, these flights can pose significant health challenges due to factors including prolonged sitting, changes in cabin pressure and reduced air quality. By understanding these impacts and taking appropriate precautions, you can mitigate the risks and maintain your physical health during and after your journey.

Prolonged sitting on long-haul flights significantly contributes to the risk of deep vein thrombosis due to restricted blood flow in the lower extremities, which can lead to clot formation.

Failure to exercise the calf muscle for prolonged periods may result in limited or poor blood circulation in the lower leg and increase the risk of deep vein thrombosis.

Studies demonstrate a clear relationship between prolonged air travel and the increased incidence of venous thromboembolism (VTE), emphasising the risk of stasis from sitting, hypoxia, and dehydration during flights.

The air quality inside aircraft cabins can significantly impact passenger health during long-haul flights. Air in the cabin is often low in humidity and recycled, leading to dryness that affect the skin, eyes and respiratory tract. This environment can exacerbate conditions like asthma and cause discomfort due to dry mucous membranes.

To alleviate symptoms associated with low cabin humidity, maintaining hydration, using moisturisers, and employing saline nasal sprays are recommended. These measures help to counteract the drying effects of cabin air, ensuring comfort and reducing the risk of respiratory irritation.

When the airplane takes off and descends, the cabin air pressure gradually changes. This affects your body in two ways.

• As the airplane rises, oxygen levels decrease. The reduced oxygen levels in the cabin can lead to mild hypoxia, manifesting as fatigue, headaches and dizziness
• Gas in your body expands upon take off and contracts when the plane descends.

Healthy individuals can tolerate hypoxia well. As for gas expansion, it may lead to a slight uncomfortable popping sensation in the ears. This happens as air escapes from the sinuses and middle ear. As the airplane descends, air flows back to these areas to equalise the pressure. This discomfort can be alleviated with ear equalisation techniques.

Swallowing and yawning: Swallowing can help to equalise the pressure in your ear. Try chewing gum, sucking on hard sweets, or sipping water during takeoff and landing to encourage swallowing. Yawning can also help.

To effectively manage the health risks associated with long-haul flights, passengers are encouraged to adopt the following proactive measures:

• Use the ClotBuster® In-Flight Passenger Foot Pump for 3 to 4 minutes every hour. This will help to activate the calf muscle pump and increase deep venous blood flow, thus reducing the risk of blood pooling and deep vein thrombosis. A study under controlled conditions on the ground found that vigorous ankle flexion with feet against resistance causes prompt recovery of lower limb venous return after prolonged immobility;
• While regular walks around the cabin during long-haul flights could be expected to avert the risk conferred by prolonged lower limb venous stasis, restrictions imposed by blockages in the aisle and by immobility during sleep make this impractical. It remains to be proved that performing the airlines’ currently recommended leg exercises while seated will be beneficial during long-haul flights;
• Avoid carbonated drinks and heavy meals. This can help minimise bloating. Consuming lighter meals and non-carbonated beverages before and during the flight reduces the volume of gas that can expand at high altitudes, thereby alleviating discomfort;
• Stand up and stretch at intervals to improve circulation;
• Wear compression stockings to promote blood flow in the legs. Compression stockings work by exerting the greatest degree of compression at the ankle, with the level of compression gradually decreasing up the garment. The pressure gradient ensures that blood flows upward toward the heart instead of re-fluxing downward to the foot or laterally into the superficial veins. The application of adequate compression reduces the diameter of major veins, which increases the velocity and volume of blood flow.

However, compression stockings do have some disadvantages. Poorly fitted stockings can cause discomfort and at worst, pressure necrosis. Other disadvantages include, no muscle activity, different sizes, difficult to wear for some people, uncomfortable for some people and there may be problems in people with arterial disease. When used, compression stockings need to be measured and fitted properly;

• Drink water frequently to stay hydrated. Avoid excessive alcohol and caffeine, which can lead to further dehydration;
• Use saline nasal sprays to keep nasal passages moist, counteracting the dry cabin air;
• Apply moisturising lotions to keep skin hydrated and prevent dryness.

Long-haul flights, while essential for global travel, come with inherent risks that can impact passengers’ comfort and well-being. By understanding the physical challenges posed by prolonged sitting, reduced cabin air quality and changes in cabin pressure, passengers can take effective measures to protect their health.

Long-haul flights may increase the risk for blood clots in some people, including people with additional risk factors, such as personal or family history of blood clots. Preventing blood clots during long-haul air travel is possible. Understanding your personal risk and learning preventive steps you can take during travelling can help.

If you are currently being treated for a blood clot, or have recently completed treatment for one, talk with your doctor before boarding a flight. They may recommend delaying travel or offering medication to help reduce your risk for serious complications.