Risk factors and Prevention of Travellers Blood Clots or Deep Vein Thrombosis (DVT)

Deep Vein Thrombosis (DVT) is also known as “Economy class syndrome”. This is a bad term as they can occur in first or business class, in buses, or in fact any prolonged travel over 4hrs. In fact, there is probably more leg movement in economy class as the seating is so uncomfortable! It is not known whether traveller’s clots differ from post-operative clots. Aisle seats have a lower incidence of DVT than window or middle seats. Short people, and tall people, also seem to have a higher incidence. Travel is not the only factor, as they can occur with prolonged squatting as with gardening. They also can occur after any surgery, although some operations are more of a concern than others. There are recognized risk factors (see below).

We are talking about blood clots that are in the veins deep inside the leg, and are known as Deep Vein Thrombosis (DVT). You can’t see these veins and so clots are diagnosed with a blood test, or an ultrasound. They are potentially lethal, as they can break off and travel along with the blood stream and lodge in the lungs. Most patients survive however.

Risk factors for DVT

  • Previous DVT
  • Recent surgery
  • Recent trauma to the leg such as in sports teams
  • Active cancer
  • Known hereditary clotting tendencies
  • Family history of DVT
  • Oral contraceptives
  • Prolonged squatting or travel >4hrs
  • Pregnancy
  • Obesity (BMI > 30)
  • Age over 40 yrs
  • Varicose Veins

The top 5 are regarded as higher risk


Walking, and compression knee length stockings are the only proven beneficial factors.

Abstaining from alcohol does not appear to help. Although unproven, drinking lots of fluids to prevent dehydration will help to minimise jet lag and makes sense.

Who should wear compression stockings? Those with more than one risk factor should definitely wear them. You only need knee high with an ankle pressure of 30mmHg. Aspirin does not appear to have any benefit in preventing DVT. If you have one of the 5 high risk factors, you should come and have a consultation with us about the risks, and possibility of adding some anti-clotting medication.

We have special calf length sequential compression stockings for males and females available, that have graded sequential pressures so that they act as pumps to minimize blood stagnating in the legs. Even if you have no risk factors, your legs will feel more comfortable and keeps the swelling down.