A Possible Reason to Fly First Class: 'Economy Class Syndrome'

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Oct. 25, 2000 -- If claustrophobia and fear of crashes weren't enough to keep you grounded, now there's a new reason to fear flying: It's called "economy class syndrome."

The term is used to describe a consequence of a medical condition known as deep vein thrombosis that occurs when people develop blood clots in the deep veins of their legs. It can happen when the blood does not move through the vessels adequately, for example, after sitting through long flights in cramped airplane seats, which could happen in the section referred to as economy class.

Affecting millions of people worldwide each year, these blood clots can travel to the lungs or other areas, causing strokes, severe organ damage, or death. Such clots have been reported after automobile trips and even after evenings at the theater, but long airplane flights seem to pose a greater risk.

A 1986 study found that during a three-year period at London's HeathrowAirport, 18% of the 61 sudden deaths among long-distance passengers werecaused by such leg blood clots. And researchers from the Hospital Pasteur inNice, France, report that travelers who sit for more than five hours onplanes are more likely to develop blood clots in their leg thannontravelers.

The most famous recent episode occurred in 1994 when former Vice PresidentDan Quayle developed a leg clot that traveled to his lung soon after aseries of airplane trips.

Now, another case of so-called "economy class syndrome" is making headlines.Newspapers report that a 28-year-old women flying from Sydney to Londondeveloped deep vein thrombosis and collapsed and died after reachingHeathrow Airport.

People at high risk for deep vein thrombosis include those with varicose veins or cancer, smokers, individuals with history of leg clots, leg or pelvic surgery or a leg injury, pregnant women, women taking birth-control pills and hormone-replacement therapy, overweight individuals, elderly people and tall people. Warning signs and symptoms include pain, warmth, and swelling in the legs and shortness of breath, experts tell WebMD.

"Risk factors, in addition to being seated in the economy class and having legs confined, are obesity and pregnancy," says Mark Adelman, MD, the director of vascular surgery at Bellevue Hospital in New York City and an assistant professor of medicine at New York University School of Medicine.

"Fliers who take birth control pills or hormone replacement therapy may be at increased risk because estrogen increases the risk of clotting," he tells WebMD.

When you sit for a long time without contracting the muscles in your legs, blood can pool in the veins resulting in deep vein thrombosis; that's why getting up and walking around the plane is the best way to prevent a clot from forming, he says.

"If you can't walk [during the] flight, flex your ankle up and down, as if you are stepping on the accelerator in the car," Adelman says. "Do this exercise about 20 times every two to four hours you are in flight."

Another problem: Plane air is dry, and fliers can easily become dehydrated. "When you are dehydrated, your blood becomes thicker, increasing risk of clots," he says. So try to drink an eight-ounce glass of water every two hours and avoid alcohol and coffee when flying, as they are dehydrating, he says.

Adelman wears compression hose when he travels and suggests other fliers do the same. They are available over-the-counter at surgical supply stores and cost about $15 per pair. Such support hose work by keeping blood from stagnating.

Taking an aspirin before flight may be of some benefit as well, he adds. Aspirin is a known blood thinner.

But some medical experts, including Louis D. Fiore, MD, an assistant professor of medicine and public health at the Boston University School of Medicine and School of Public Health and the chief of oncology at the VA Boston Health Care System, have their doubts about economy class syndrome.

"There are multiple risk factors for developing blood clots in the leg," he says. "There are genetic risk factors and then superimposed on that are environmental risk factors such as having surgery or a trauma," he tells WebMD.

But "flying is a very minor risk factor," Fiore says. "Immobilization in the absence of illness is a low risk for deep vein thrombosis. If immobilization on a airplane flight is enough to put you over the edge, something else will do it will first."

In other words, "if you don't have problems with blood clots, disregard the syndrome. It's unnecessary anxiety. If you have a history of blood clots, then prolonged immobilization from any cause should be avoided," he says.

There's a sector of the population that is genetically predisposed to developing blood clots in the leg, Fiore says. While there are genetic tests to see if you have these high-risk genes, "they are expensive and not worth the money," he says.

Other ways to prevent deep vein thrombosis while flying include the following:

  • Book a seat in an exit row, a bulkhead seat, or an aisle seat; walk up and down the aisle about once an hour.
  • Wear loose-fitting clothing.
  • Don't smoke.
  • While in your seat, contract your calf muscles from time to time by clenching your toes. One exercise, suggested by British Airways, is to bend your foot upward, spread your toes, and hold for three seconds, then point your foot down, clench your toes, and hold for three seconds.
  • If you are at high risk of blood clots, ask your doctor if you should take aspirin before flying to inhibit blood clotting.
  • Don't cross your legs or sit on the edge of your seat; these positions can reduce blood flow in your legs.

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