Deep Vein Thrombosis

Deep vein thrombosis (DVT) is the formation of a blood clot (thrombus) within a deep vein, predominantly in the legs. For patients with myeloproliferative neoplasms (MPNs) it is important to avoid the risk of DVTs wherever possible. 

Common signs and symptoms of DVT include pain or tenderness, swelling, warmth, redness or discolouration, and distention of the surface veins, although about half of those with the condition have no symptoms.  It is important to be aware of the signs and consult with your GP or haematologist if you do display any of these symptoms.


All long journeys by any mode of transport, by plane, car or train, may increase the risk of deep vein thrombosis (DVT). However, the risk is not as great as the media would suggest. We estimate the risk to be only one DVT per million passengers on flights over six hours. Plan ahead, stay hydrated and stretch your legs to ensure a safe trip.

Prevention comes first

Prevent DVTs by taking a few simple steps:

  • Stay hydrated Avoid alcohol and excessive consumption of caffeine, and drink plenty of water instead.
  • Keep moving Take breaks during a long drive or flight and walk around. Flex your ankles regularly to contract calf muscles.
  • Wear flight socks It’s a good idea to wear flight socks or pressure tights for journeys longer than four hours unless tights are contraindicated, for instance, if you suffer from poor circulation to legs or ulcers due to arterial disease.
  • Stay straight Avoid crossing your legs or ankles when seated.

Plan for medication needs

When travelling, always make sure you take plenty of your medication in case your stay is prolonged. If you are travelling with liquid medication it is wise to avoid putting it in your luggage that will be put in the hold as in the luggage hold, temperatures drop considerably and may freeze some medicines. Check with your airline for restrictions and take a letter from your haematologist to ensure that you can take your medicine on board with you.

Carry a list

It’s useful to carry a list of your medications and the details of your medical history if it is complex.  Our medical alert card is also useful to ensure health care professionals are made aware of your MPN condition.

Additional protection

Most MPN patients do not require additional protection to prevent clots.  However, your doctor may advise that you take an injection of heparin prior to the flight, especially if:

  • You have had recent or multiple thromboses
  • You have experienced a clotting event
  • You are pregnant
  • You have delivered a baby or miscarried less than six weeks before travel
  • You have recently undergone surgery
Heparin is simple to give and your haematologist can provide a letter explaining its use for airline security. Talk to your doctor about your travel plans. Download our travel and insurance booklet