Fear of flying

In October 2000, a 28-year-old woman collapsed and died after a long-haul flight from Australia to London. Her death was the result of a blood clot, caused by deep vein thrombosis (DVT), which travelled to her lungs. This incident prompted a meeting hosted by the World Health Organisation for doctors and airline officials to discuss the problem. The outcome was that British Airways, and several other airlines, now issue information to passengers before and during flights advising them on general well being in the air.

Deep vein thrombosis is defined as the formation of blood clots, which usually originate in the lower legs. These clots are caused either by poor circulation, or being inactive for long periods of time. DVT occurs as blood collects in the veins of the lower legs, forming a clot. As this clot grows, parts of it, called emboli, can break off and travel through the blood. Complications develop when emboli become lodged in the lungs, or cause blockages in other parts of the circulation system like the brain and heart. The result is chest pain, shortness of breath and, in some cases, sudden death. Deep vein thrombosis effects men and women equally.

Economy-class syndrome, a term frequently used to describe DVT, is misleading because any passenger, regardless of ticket class, can be affected. Despite the recent publicity surrounding passenger deaths from DVT, a recent study in The Lancet journal argues that although there is a link between long-distance flights and ‘economy-class syndrome', most people are not at risk.

Dr John Scurr, a vascular surgeon at London's Middlesex Hospital, has done extensive research on DVT and claims most people have little cause for worry. In his study, he examined 200 passengers before and after they had been on long-distance flights. Although 10 per cent of passengers developed small blood clots, none of the clots developed into a serious problem.