There may be an increased risk of developing blood clots with long distance air travel, however the risk is small.

While taking warfarin you have a very low risk of developing a blood clot while flying

as your blood is already thin, therefore you don’t need to take any special precautionsDrink plenty of fluid

When you have completed your warfarin therapy you should take precautions to reduce the possibility of another blood clot. It is unlikely that you are at any risk for a short flight of less than 6 to 8 hours, however for a longer flight it is recommended that you do the following.

  • Avoid excessive alcohol as this can dehydrate you
  • Don’t take sleeping tablets
  • Do passive leg exercises
  • Occasionally get up and walk around the plane
  • Wear below knee compression stockings

Some people recommend taking low dose aspirin before a flight as this thins the blood slightly. This is not one of our standard recommendations as there is no evidence that aspirin reduces the risk of travel related blood clots, but if you have taken aspirin previously without side-effects there is no harm taking this treatment.

If your doctor feels that you have a high risk of developing another blood clot, you may be advised to have an injection of low molecular weight heparin before a long flight. You should discuss this with your doctor if you are uncertain about your risk of further clots.