A hospital based next to one of the world's busiest international airports has estimated that up to 2,000 passengers a year worldwide die from post-flight deep-vein thrombosis.

Ashford General Hospital, which has the closest accident and emergency department to London Heathrow Airport, UK, says it has dealt with about 10 deaths a year resulting from post-flight deep-vein thrombosis (DVT) over the past three years.

A hospital projection of its figures in relation to the number of passengers who pass through Heathrow has concluded that up to 2,000 passengers a year worldwide may die of flight-related DVT. Precise figures are difficult because many hospitals do not record whether DVT patients have recently been on an aircraft.

The hospital's revelation is likely to refuel a controversy ignited following the death of a young woman who died following a trip from Australia to London. Partly as a result of publicity surrounding that incident British Airways has decided to issue leaflets to its long haul passengers giving advice on how to reduce the risk of DVT - which it calls "traveller's thrombosis" - while flying.

The risk can be increased - particularly in the old, smokers and the obese - through long periods of forced inactivity, which is not unique to airline travel, cardio-vascular consultants make clear. The dry air at altitude, however, can lead to dehydration, which raises the risk.

Source: Flight International