Thrombo-embolic episodes related to flight, such as deep vein thrombosis (DVT) and pulmonary embolism, are likely to increase over the coming decades with the expected expansion of long range air travel. Although DVTs are often referred to as the 'Economy Class Syndrome' they may also affect other passengers. Long hours of relative immobility and possibly cramped seating may well be precipitating factors

DVT risk factors

• Age: greater than 40 years (especially the elderly)
• Previous thrombotic episode (especially pulmonary embolism)
• Documented thrombophilic abnormality
• Certain haematological disorders
• Malignancy e.g. cancer
• Congestive heart failure
• Recent surgery (especially lower limbs)
• Pregnancy
• Post-thrombotic Syndrome
• Chronic venous insufficiency
• The pill or HRT
• Dehydration

There are also risk factors specific to air travel -

• Immobility
• Cramped position
• Dehydration due to the excessive use of alcohol
• Compression of popliteal vein by the edge of the seat
• Seated posture (especially when sleeping)
• Tall and short individuals

There are several simple methods by which you can reduce the risk of a DVT

• Try to keep your thighs clear of the edge of your seat. If travelling in Business or First Class keep your feet up on the leg rests at the highest elevation. Alternatively you can rest your feet on your hand luggage.
• Take some exercise during the flight. This can be done by moving around the aircraft cabin or by using a leg exerciser.
• Drink plenty of water to avoid dehydration. Avoid too much alcohol.
• Wear elastic flight socks or support stockings (this is particularly important for passengers with varicose veins).
• Take a low dose aspirin (100 - 150mg) the day before, during a long haul flight and for three days after.
• Walk briskly for at least half an hour before take-off.

Consult your GP if you think you are suffering from any medical condition that might be affected by your flight. Patients at particular risk of a DVT may be prescribed Low Molecular Weight Heparin.