Deep Vein Thrombosis (DVT) and Air travel

Movement of body parts has very important role in helping blood from legs and other peripheral parts of body to return back to heart. The prolonged immobility may lead to formation of blood clots into deeper vessels (particularly veins of extremities, i.e. leg veins). This is of vey much importance if passenger belongs to a group of people who are more likely to develop blood clots in deeper veins. This condition is called as DVT or Deep Vein Thrombosis which results in in-patency of blood vessels (tubes) and swelling of legs and feet due pooling of blood. It is concluded by various researches that DVT can occur as a result of prolonged immobility, for instance during long-distance travel, whether by car, bus, train or air. WHO, WRIGHT study Phase I indicates that the risk of venous thrombo-embolism approximately doubles after a long-haul flights (> 4 hours) and also with other forms of travel where travelers are exposed to prolonged seated immobility. The risk depends on the duration of the travel and number of flights within a short period. Although commonly formed small the clotsdo not cause any symptoms, larger clots may cause symptoms such as swelling of the leg, pain on touch and pressure and soreness. Sometimes a piece of the clot may break off and go with the bloodstream to become lodged in the lungs (known as Pulmonary Embolism which may cause chest pain, shortness of breath and, in severe cases, sudden death) many hours or even days after the formation of the clot in the leg.


Other predisposing to DVT are previous DVT or pulmonary embolism, history of DVT or pulmonary embolism in a close family member, use of contraceptives Pills or hormone replacement therapy (HRT),  pregnancy, recent surgery or trauma, cancer, obesity and some inherited blood-clotting abnormalities. Expert well advanced opinion is of help for people with one or more of these risk factors.


The incident of DVT can be minimised by moving around the cabin during long flights. Exercise of the calf muscles can stimulate the circulation, alleviate discomfort, fatigue and stiffness, and may reduce the risk of developing DVT. Hand luggage should not be placed where it restricts movement of the legs and feet, and clothing should be loose and comfortable. Any preventive medicine should not be taken without clinician’s recommendation.