Fatal Blood Clot Risk Doubles in Long Travels, UNWTO Study Reveals

The United Nations World Health Organization releases findings from Phase I of the UNWHO research into Global Hazards of Travel Project which examined the risk of VTE is increased by air travel and to determine the magnitude of the risk.

A study by the United Nations World Health Organization (UNWHO) has found that the risk of developing fatal blood clots during travel doubles after the passenger has been seated for four hours or more.

The condition, known as venous thromboembolism (VTE), involves first the formation of a clot, or thrombosis that develops in a deep vein –usually the leg. According to the UNWHTO, this condition is called Deep Vein Thrombosis (DVT) and can be potentially life-threatening if the thrombosis then breaks off and travels through the body to the lung where it becomes lodged and blocks blood flow.

“This latter condition of VTE is known as pulmonary embolism. Symptoms of DVT are pain, tenderness and swelling, while symptoms of the embolism include chest pain and difficulty breathing,” the UNWHO said.

The findings come from Phase I of the UNWHO research into Global Hazards of Travel Project which examined the risk of VTE is increased by air travel and to determine the magnitude of the risk.

“The study does confirm that there is an increased risk of venous thromboembolism during travel where the passenger is seated and immobile over four hours, whether in a plane, train, bus or car,” said Dr. Catherine Le Galès-Camus, WHO assistant director-general for Noncommunicable Disease and Mental Health.

The UN health official, however, pointed out that “it is important to remember that the risk of developing VTE when traveling remains relatively low.” The UN specialized agency claims that even with the increased risk, the absolute risk of developing VTE, if seated and immobile for more than four hours remains at about 1 in 6,000.

In addition to travel lasting more than four hours, other factors contributing to the possibility of developing VTE include obesity, use of oral contraceptives and a family history of increased clotting tendency, WHO said. As the risk of VTE remains elevated for about four weeks after a trip is over, those who travel multiple trips of short periods of time are also potentially at risk.

According to the UNWHO, the study did not explicitly investigate preventative measures against DVT and VTE, but the experts said that up-and-down movements of the feet at the ankle while seated can promote blood circulation. Phase II of the study will focus on identifying effective preventive measures.

The findings come from Phase I of the World Health Organization Research into Global Hazards of Travel Project. The first phase aims to confirm whether the risk of VTE is increased by air travel and to determine the magnitude of the risk.