Since 1993, 44 Japanese are believed to have developed economy-class syndrome, a potentially fatal condition characterized by poor blood circulation and breathing difficulties caused by the strain of long flights in cramped seats.
The study by the transport ministry-affiliated Koku Igaku Kenkyu Center found that four of the 44 died of the syndrome. Women made up the majority of the patients, while those who didn't leave their seats were found to be particularly susceptible. The survey covered an eight-year period from 1993.
The syndrome, in which dangerous blood clots form, has been attributed to discomfort in tight seating on long-haul flights. Blood circulation is blocked and breathing difficulties can arise.