Deep Vein Thrombosis

Deep vein thrombosis is a serious health problem associated with long haul flights. This general information will help you learn what personal health factors may increase your risk of this problem. If you feel that you are at an increased risk of a thrombosis and are required to travel for the University pplease contact the Occupational Health Service.

Several factors as increase an individual’s risk of a Deep Vein Thrombosis (DVT). These include:

  • History of DVT or pulmonary embolism
  • Blood disorders (e.g. thrombocythemia, antithrombin deficiency)
  • Pregnancy and immediate post natal period/ breastfeeding
  • Malignancy
  • Heart failure or recent heart attack
  • Recent surgery (in past 3 months) especially to the pelvis or lower limbs
  • Oestrogen therapy (e.g. oral contraceptive pill)
  • Smoking
  • Dehydration
  • Long Haul Flight

Long-haul flights that typically last for 8 to 10 hours are considered one of the highest risks. The risk of DVT increases during the two weeks following a long haul flight. The risk increases with the length of journey and if the health risk factors above are present.  It is probably due to a combination of immobilisation, dehydration and underlying risk factors. All travellers, including travellers by bus, train and car, are equally at risk. Plane travellers who travel on the window seat have double risk of DVT.

Although many DVTs are asymptomatic , symptoms of DVT include pain in the calf accompanied by swelling and redness. The affected area is often warmer and there may also be fluid (oedema). Pulmonary embolus is a serious complication and can be life threatening; sudden onset of breathlessness is the most common clinical feature.

DVT Prevention

Travellers intending to travel long haul should consider measures to reduce the risk of DVT:

  • Avoid dehydration and excessive consumption of alcohol or caffeine
  • Do not wear constrictive clothing around the waist or lower extremities.
  • Walk around the cabin as much as is practical at regular intervals during the flight
  • Regularly flex and extend the ankles to encourage blood flow from the lower legs
  • Take regular deep breaths
  • Avoid stowing hand luggage under the seat as it restricts movement

Any traveller with significant risk factors should seek medical advice and be considered for prophylaxis such as the use of compression stockings, which reduce the risk of DVT and also reduce swelling associated with long haul flights. It is vital that compression stockings are correctly measured and properly fit as ill fitting stockings could further increase the risk of DVT. Aspirin is not recommended for the prevention of venous thrombosis during travel.