Deep Vein Thrombosis (DVT) is the formation of a blood clot in a deep vein, usually in the thigh or calf. DVT becomes dangerous if the blood clot breaks loose, travels in the bloodstream and lodges in an artery of the lung. The resultant serious condition is called Pulmonary Embolism.
Sitting in cramped seats in the same position for long periods of time, such as with long haul flights (long distance bus or car travel can also bring on DVT) increases the risk of this condition, particularly for some individuals with pre-existing risk factors, such as:
- Increasing age (over 40 years)
- Oestrogen hormone therapy, including oral contraceptives and hormone replacement therapy
- Former or current malignant disease
- Personal or family history of DVT
- Blood disorders leading to increased clotting tendency
- Recent major surgery or injury, especially to the lower limbs or abdomen
- Heart failure
- Varicose veins
Travelvax believes that the more risk factors that are present, the greater the need for a pre-flight medical review.
Anticoagulant medication such as Heparin and graduated support stockings may be advisable for high-risk travellers and should be prescribed by a physician.
It has been claimed that passengers on flights lasting more than 8 hours as well as travellers with multiple risk factors are at increased risk of developing DVT. A study by British Airways found that the risk of a health incident, which includes DVT and other diseases, may be in the order of 9 per 100,000 passengers.
- Stop or greatly reduce cigarette intake for two weeks before flying
- High-risk travellers should seek aisle seats near an exit if possible to maximise ease of movement, consider upgrading to Business Class, where possible
- High risk travellers should see their doctor regarding low molecular heparin or graduated support stockings
- Move legs and feet for three to four minutes per hour while travelling
- Drink adequate water to achieve light yellow-coloured urination
- Minimise alcohol and caffeine intake (because of the diuretic effect)
- Disembark at any transit stops and walk for 10-20 minutes, if possible
- Wear comfortable clothing, particularly loose around the waist and groin, as well as graduated support stockings.
Recognise the early symptoms of DVT (tenderness and redness in the affected area, swelling of the limb, fever, joint pain and soreness or sudden unexplained cough).
Seek urgent medical review if any of the following symptoms occur, as specific treatment is available:
- Pain, usually in the calf or thigh
- Swelling, usually in one leg
- Warm reddened skin that is tender to touch
- Shortness of breath.