Travel and Thrombosis


Planning on travelling overseas this coming holiday season? Don’t forget to pack your compression socks to avoid Deep Vein Thrombosis (DVT).


What is DVT?

DVT happens when a blood clot forms in a deep vein somewhere in the body. It is most common in the deep veins of your lower leg (calf), and can be very serious.

There is evidence that long-haul flights (lasting over four hours or over 4000 kms) can increase your risk of developing DVT. The risk is mainly the result of sitting down for long periods of time, which can happen during any form of long-distance travel, whether by car, bus, train or air.



Many of the blood clots that cause DVT are small and don’t produce any symptoms. Your body will usually be able to gradually break them down with no long-term effects.

Larger clots can partly or completely block the blood flow in your vein and cause symptoms such as:

  • Swelling of the affected leg.
  • Pain and tenderness in the affected leg
  • Difficulty standing and weight bearing on the affected leg.
  • A change in the colour of your skin; for example, redness
  • Skin that feels warm or hot to the touch.

Possible complications of DVT

Developing DVT can have some serious complications. These include the following:

  • Limb Ischaemia

This is a rare complication that only happens in a very extensive DVT. Because of the blood clot, the pressure in your vein can become very high. This can block the flow of blood through your arteries, so less oxygen is carried to the affected leg. This can be painful and lead to skin ulcers, infection and even gangrene.

  • Post-thrombotic Syndrome

This happens if DVT damages the valves in your deep veins, so that instead of flowing upwards, the blood pools in your lower leg. This can eventually lead to long-term pain, swelling and, in severe cases, ulcers on your leg.

  • Pulmonary Embolism

This is the most serious complication of DVT. A pulmonary embolism (PE) happens when a piece of the blood clot from a DVT breaks off and travels through your bloodstream to your lungs, where it blocks one of the blood vessels in your lungs. This is serious and in severe cases, can be fatal.



  • Physical Examination

Your GP will ask about your symptoms and examine you. If he or she thinks that you might have a DVT, you may be referred to a specialist.

  • D-Dimer blood test

This measures a substance that develops when a blood clot breaks down. If this is negative, it’s unlikely that you have a DVT.

  • Doppler Ultrasound

This is a test that uses sound waves to look at your blood as it flows through your blood vessels. It’s the best test to detect blood clots above your knee.

  • A Venogram

In this test, a dye is injected into your vein, which shows up the vein on X-ray. This is the best way of showing clots below your knee.


Medicines- Anticoagulant medicines are the standard treatment for DVT. They change chemicals in your blood to stop clots forming so easily and old ones from getting any bigger. Anticoagulants include heparin and warfarin.

Compression Stockings- Your doctor may ask you to wear these to ease your pain and reduce swelling, and to prevent post-thrombotic syndrome.

Prevention of DVT while travelling

There are a number of things you may be able to do to reduce your risk of developing DVT while travelling. These include:

  • Take short walks – if you’re a passenger, walk up and down the aisle of the coach, train or plane.
  • Exercise the muscles of your lower legs by regularly bending and straightening your toes, ankles and legs.
  • Wear loose-fitting clothes.
  • Keep hydrated/ drink more water.
  • Don’t drink too much alcohol or too many drinks that contain caffeine.
  • Avoid taking sleeping tablets.
  • Wear compression stockings.
If you develop swelling or pain in your calf or thigh, or if you have breathing problems or chest pain after travelling, seek urgent medical attention.


For more information visit:


Heart Foundation of Australia