Deep vein thrombosis risk increased by airplane window seats, experts say

"Economy class syndrome," which suggests that air passengers in cheaper seats are at risk of deep vein thrombosis (DVT), is a myth, according to US researchers, who warned Tuesday that the condition was more likely to affect any travelers sitting in window seats.

Experts from the American College of Chest Physicians said that economy class passengers on flights of more than four hours were no more likely to suffer from DVT than those in business and first class—but sitting next to a window made passengers less likely to get up and walk around.

DVT, the formation of serious blood clots in the veins, has been associated with long-haul travel and is a potentially fatal disorder.

"Traveling in economy class does not increase your risk for developing a blood clot, even during long-distance travel," according to Dr. Mark Crowther, of McMaster University in Ontario, Canada. "However, remaining immobile for long periods of time will."

He added, "Long-distance travelers sitting in a window seat tend to have limited mobility, which increases their risk for DVT. This risk increases as other factors are present."

Female passengers taking the contraceptive pill, travelers over 70, cancer patients and the severely obese were warned that they had a higher risk of developing DVT—and the risk was "strongest for flights over eight to 10 hours."

The researchers also dispelled the myth that dehydration increases the chances of suffering from DVT and said that passengers who drink alcohol on a flight were not any more at risk than nondrinkers.

The study, published in the journal Chest, stressed that the risk of developing DVT from a flight is "rare" but recommended that passengers walk around regularly to stretch their calf muscles.