According to the Associated Press, the WHO report notes that the risk of blood clots during a flight is highest among passengers who are at risk due to health conditions, as well as among women who have taken birth control pills before the flight. In addition, taking sleeping pills, sedatives, and alcohol during a long flight can weaken the body's protective response to physical inactivity.
The WHO's conclusions are based on the results of studies conducted by scientists from the UK, Switzerland, and the Netherlands. The impetus for this scientific work was the sudden death of a British woman in 2000 after a long flight from Australia. 28-year-old Emma Christofferson died from pulmonary embolism (a condition in which a blood clot suddenly detaches from the venous wall and blocks the pulmonary arteries, leading to death). As is known, pulmonary embolism is a complication of venous thrombosis.
According to the WHO, one in 15 airline passengers is at risk of developing thrombosis during any flight lasting more than four hours. As noted in the report of this international organization, some people are predisposed to developing this dangerous condition due to genetic reasons or a sedentary lifestyle. The risk group includes the elderly and those who are overweight. Interestingly, people of short stature are also at increased risk during flight because they are less mobile in the seat due to dangling legs, as well as very tall people who are immobile because the 'standard' seat is too small for them.
"If you are in the risk group, you should consult your doctor before the flight," notes WHO expert Shanti Mendis. According to her, the main enemy during flight is immobility. She is confident that passengers can sharply reduce the risk of thrombosis if they stand up for a short walk at least once every hour of the flight or periodically do exercises to stretch numb muscles. Of course, those predisposed to diseases related to blood pressure should also always have a blood pressure monitor with them, which can be purchased on the website "MedTekhnika".
Furthermore, according to Mendis, studies have shown that in women who have taken contraceptive drugs before the flight, the risk of developing thrombosis during the flight increases by 10 (!) times. Signs of sudden formation of thrombosis during air travel are sharp pain or cramps in muscles and joints, as well as swollen legs.
The warning in the WHO report is far from the first alarm signal. For a long time, doctors have been urging leading global aircraft manufacturers to increase the space between seats. In addition, they argue, aircraft cabins should provide special seats for very tall, short, and overweight people. However, the world's aviation giants have not yet heeded these calls.
By the way, recent studies by Western scientists have shown that the risk of thrombosis also exists on short-haul flights. For example, experts studied the condition of passengers who flew from the UK to Italy and concluded that in some travelers, thrombosis can form within two to three hours after takeoff. During the experiment, passengers aged 25 to 65 underwent ultrasound examinations for blood clots before and after the flight. Blood clots were found in 4.3% of the passengers on this flight who were in the risk group.
The WHO report notes that although the danger of thrombosis also exists during train or car travel, airline passengers are much more at risk. Meanwhile, the International Air Transport Association clarified that the planet's inhabitants make about 2.2 billion trips by air annually, but the organization does not specify what proportion of these flights are long-haul.
Last October, medical specialists were pleased by Australian manufacturers who began producing special socks that can reduce the risk of venous thrombosis during long flights. These are ordinary knitted socks laced with silver threads and equipped with a portable battery that sends electrical impulses to the person's leg via wires. As scientists have found, these unusual socks can increase blood circulation by one and a half times, supplying the muscles and skin with enough oxygen. In addition, the silver threads have a hygienic effect: they can eliminate unpleasant odors. True, such unusual socks are not cheap: about $190, but the manufacturers claim they can be washed more than 70 times.