Should you sock it to DVT?
By Nick Easen for CNN
(CNN) -- Wearing tight flight socks will reduce the risk of so-called "economy class syndrome," according to a recent scientific study.
The study showed that when compression socks were worn, one in 100 passengers had a potentially fatal blood clot -- known as deep vein thrombosis (DVT) -- compared to six times that without support around the legs and ankles.
The research shows that wearing the socks supports the veins and reduces tenderness and swelling.
Professor Gianni Belcaro of G.d'Annunzio University in Pescara, Italy who carried out the survey says business travelers could be at a greater risk to the syndrome.
"If you travel a lot you may [get] a clot, on average [one] for every 60 hours of flight," Belcaro told CNN.
"It is not a disease, it is a condition. It is common and may cause problems and costs."
"Companies when sending staff for missions should supply stockings to avoid legal claims related to work," he added.
The socks are no ordinary cotton, low-slung affair but graduated compression ones that give tight ankle support and a firm-hold up to the knee.
Currently the Aviation Health Institute sells the socks online for $19, and says that DVT is likely to increase over the coming decades with the expected expansion of long-range air travel.
Belcaro told a conference in Lisbon earlier this month that the best way to prevent DVT would be for airlines to stop cramming people into planes.
The Italian study followed 205 people at high risk of deep vein thrombosis because they suffered from heart disease or had previously suffered from DVT.
Half the group were supplied with socks for an 11 to 13 hour flight, the other half were sockless. Before and after the flight the passengers had their veins scanned.
Out of the 103 who wore the special flight socks only one developed a minor blood clot, while six who were traveling without them developed a clot.
The results of the study come after a court in London ruled against a number of families of DVT victims.
Earlier last month a High Court judge ruled against 24 claimants who were pursuing an appeal against 16 airlines, saying the carriers should have made passengers more aware of the risks of long-haul flights.
Restricted movement and space
Belcaro plans to expand his study of DVT to those who sit for hours surfing the Internet. He believes this group may also have a higher propensity to develop blood clots.
Another study by Professor Maria Cesarone also indicates that pilgrims traveling to several holy locations in Europe in buses may have a higher incidence of DVT.
The "Pilgrim syndrome" study looked at bus journeys longer than seven hours to holy venues such as Lourdes in France.
DVT, dubbed "economy class syndrome" because of its association with restricted space on long haul flights, is a blood clot that develops when movement is restricted.
Low air pressure and dry air in-flight causes some of the fluid components of the blood to move out of the blood vessels into surrounding tissue.
This causes ankles and feet to swell and makes the blood thicker.
The clot, usually in the leg, can travel to the brain or lungs and can lead to a stroke or death. There is a higher prevalence in those with heart defects.
It is due to a combination of poor circulation, which occurs when a person sits still for long periods.
Other factors that increase the natural tendency of the blood to clot can also play a part, including the contraceptive pill, recent surgery, pregnancy and hormone replacement therapy.