Who is at Risk from Deep Vein Thrombosis (DVT)?

Some people are more susceptible to deep vein thrombosis (DVT) than others. In general, the risk of DVT increases with age, with less than 1 in 3,000 people aged under 40 affected, rising to 1 in 500 in those over the age of 80. However, some studies have suggested that up to 1 in 30 passengers on long-haul flights will develop DVT.

However, as long as you take reasonable precautions and exercise every so often, you shouldn't let the worry of DVT dissuade you from flying. If you have any concerns or doubt, consult your local GP or travel clinic for expert advice.

High-Risk Categories

Whilst studies may not totally agree on the numbers of people affected, they do generally agree on those who fall into the high-risk category for developing DVT. These include anyone who has (or has had):

• Medical conditions such as heart or circulation problems or blood diseases
• Previous thrombotic episodes (especially pulmonary embolism)
• Undergone recent medical surgery or treatment (especially lower limbs, and in particular the hips or knees)
• Congestive heart failure
• A malignant disease e.g. cancer
• Dehydration

Other high risk groups include:

• Anyone who is over 40 years of age
• Pregnant women (or those who have recently given birth)
• Women who are on hormonal medication (including the oral contraceptive pill and oestrogen) containing hormone replacement therapy
• Anyone who is reasonably tall or short (due to their seating positions)
• Anyone who has suffered a stroke

Research has also suggested that smoking, obesity and varicose veins can also compound susceptibility to DVT. However, it should also be noted that people who do not fit the criteria may also develop DVT, but their chances of doing so are much slimmer.

Other Risk Factors

Deep vein thrombosis becomes more of a risk factor if you experience:

• Compression of the popliteal vein by the edge of the seat
• A cramped position for the duration of the flight
• Extended periods of immobility
• Dehydration as a result of alcohol intake

Above all, those at greatest risk are travellers who fail to move about and exercise. One sign to watch out for is swollen feet or ankles, caused by poor circulation, and exacerbated by the low air pressure in the aircraft cabin. Whilst having swollen feet or ankles does not indicate the onset of DVT, it does indicate that you may have poor circulation, and you should therefore take every step to minimise the risk of DVT.