Economy class syndrome
Economy class syndrome was coined in the late 1990s when it turned out that people who has traveled long distances by aeroplane were at an increased risk for thrombosis, especially deep venous thrombosis and its main complication, pulmonary embolism. Although all these diseases had been recognised for a long time, the possibility of litigation against
airline companies brought them into the limelight when this "syndrome" was reported.
The mechanism for thrombosis in travellers is probably due to a combination of immobilisation, dehydration and underlying factors. Patients with disease that predisposes them for thrombosis, such as antiphospholipid syndrome or cancer, are probably at a much greater risk.
Prevention consists of adequate hydration (drinking, abstaining from alcoholic beverages and caffeine), moving around and calf muscle exercises. In patients with a known predisposition for thrombosis, aspirin is often prescribed, as this acts as a mild anticoagulant. Severe risk for thrombosis can prompt a physician to prescribe injections with low molecular weight heparin (LMWH), a form of prophylaxis already in common use in hospital patients.
People who have a history of cardiovascular disease, stroke or thrombotic episodes (blood clots) are at risk of getting blood clots in their legs during airplane flights of 10 hours or more. But these aren’t the only people who can have this problem. This condition, known as deep vein thrombosis (DVT), also can affect healthy people, even athletes. Developing DVT after long plane rides is often called "economy-class syndrome" or "coach-class syndrome," because seating and leg room are particularly cramped for passengers in economy class. However, first-class and business-class passengers also get DVT, so this problem isn’t solely due to sitting still in tight quarters for many hours. Other factors -- such as low cabin pressure, low humidity and dehydration -- all may contribute. These factors are constant throughout the plane.
People with cardiovascular disease and those at risk for clots in their legs may benefit from a single dose of heparin. This drug prevents clots from forming and is effective in reducing the risk of DVT in high-risk patients.
Doing repeated leg exercises, drinking more water and reducing alcohol intake during long flights is probably good advice. These steps aren’t scientifically proven to prevent traveler's thrombosis, but they’re common sense.