Travel Guides.

Hazards, illnesses, and diseases abroad

Deep Vein Thrombosis (DVT)

There has been a lot of publicity about the risks of blood clots in the legs as a result of long-haul flights, so-called 'economy class syndrome'. A deep vein thrombosis (DVT) is a clot which forms in the veins of the legs which run deep inside the leg i.e. not the superficial veins which are visible just under the skin. The danger of a DVT is that part of the clot can occasionally break off and become lodged in the lung (something called a pulmonary embolus or PE). This can be dangerous depending on how large the clot is and where it lodges itself.

There are several things that can make a DVT more likely to happen, one of which is reduced blood flow such as occurs in the legs when someone sits in one position for any length of time. As a result, some people have developed DVT after long-haul flights.

However, thromboses can occur after any long journey in a car, coach or train and so far there is no evidence to suggest that flying is in itself a specific risk factor.

Studies have shown that most DVTs occur in people who have at least one other risk factor for thrombosis. These include:

• Previous personal or close family history of thrombosis.
• An abnormality of the blood clotting factors.
• Certain forms of heart disease such as abnormalities of the heart rhythm or the valves of the heart.
• Current malignant disease.
• Hormone treatment including the oral contraceptive pill or oestrogen-containing hormone replacement therapy (HRT).
• Pregnancy.
• Recent major surgery.
• Recent immobility in the previous day(s).

Dehydration, smoking or obesity may also play a part in increasing the risks. The symptoms and signs of a DVT are pain and swelling in one, or (rarely), both calves. The leg may also have a different colour to usual due to the congestion of the veins as a result of the back pressure produced by the blockage. If in doubt, seek medical advice.

There are some measures that can reduce the chance of developing a thrombosis including:

• Performing regular leg exercises such as moving the feet and stretching the arms and legs or occasionally walking up and down the aisle.
• Trying to avoid crossing your legs since this exacerbates the 'pooling' of blood in the legs.
• Maintaining a good fluid intake (preferably not alcoholic since this can actually lead to a degree of dehydration).
• Avoiding smoking.

In otherwise healthy people there is a degree of controversy as to whether or not taking aspirin before the flight is truly preventative and it does carry a small risk of bleeding from the stomach. However, those people with particular risks of developing a thrombosis should discuss with their doctor whether or not they should take aspirin or use other preventative measures such as wearing special stockings or taking additional anti-clotting medication.

Further information on Deep Vein Thrombosis (DVT) can be found in the DVT Safety Zone and on the NHS Direct website.

Disclaimer
The information contained within this website is intended as a general guide only and is not necessarily comprehensive. You should seek appropriate professional advice when travelling abroad. AXA Insurance will not be liable for loss or damages arising, in contract, tort or otherwise, directly or indirectly from the use or reliance upon any information contained in this website.