Dear Dr Makis,
A friend of my recently developed a clot in her leg after travelling on a long flight, she has needed to start blood thinning medications as a result. I’m going on a flight to New Zealand later this year, how can I protect myself from the same thing happening to me?
Aimee.
Dear Aimee,
Long distance travel is a risk factor in the development of blood clots. The risk is not confined to air travel; it increases with the duration of travel and is more common in those with pre-existing risk factors.
Prolonged periods of immobility can lead to slow blood flow in the veins which increases the risk of developing a blood clot within a deep vein in the body; this is called deep vein thrombosis (DVT). Blood clots most commonly form in the legs. If parts of the clot break off and travel to the lungs, this can block blood vessels and is called pulmonary embolism (PE) which is a potentially life-threatening condition.
Although the absolute risk of developing DVT or PE after a long haul flight is very small, the risk is increased if you have pre-existing risk factors. These include,
A history blood clotting abnormalities; if you have cancer, whether untreated or currently on treatment; if you are pregnant or it is less than 6 weeks since delivery; a history recent surgery; recent serious injury or trauma; chronic heart or lung disease; a close family member has a history of DVT or PE; if you are over 60 years of age; if you are taller than 1.90m or shorter than 1.60m; if you have varicose veins; if you have mobility problems; if you are obese; if you are taking combined oral contraceptives (the pill) or hormone replacement therapy (HRT).
There are general measures that we all should all follow to try and reduce our risk irrespective of the presence of having any of the above pre-existing risk factors. Getting out of our seats and move around as much as possible. If you can choose an aisle seat as this is known to encourage passengers to get up and move around during the journey. While seated carry out calf exercises by flexing and extending your ankles and rotating your feet and ankles in a circular motion. Try to avoid placing cabin baggage where it can restrict your leg movement.
Although it is sometimes nice to have an alcoholic drink during your journey, try and avoid excessive alcohol consumption and the use of sleeping tablets or tranquilisers as this may discourage you from getting up and moving. Keep hydrated with water, this helps to keep you moving by getting up and going to the toilet.
We used to advise some people to take aspirin to help prevent a clot developing. It is now accepted that there is no place for aspirin in the prevention of travel related DVT or PE.
If you are at an increased risk of DVT or PE, anti-embolism stockings (AES) might be recommended to reduce your risk. You should discuss this with your doctor if you are unsure if you may need these. It is important that you ensure you buy the correct type and size of stocking and know how to wear them correctly. Please read the product instructions and information carefully.
If you are at a higher risk of thrombosis, then do consult with your doctor before you fly as the use of Low molecular weight heparin can be considered to reduce your risk. This treatment is administered by injection and must be prescribed by your doctor and used under their direction.
Follow this advice and your risk of developing a thrombosis will remain low. If, however you start to develop swollen, painful legs especially if one is more so than the other, chest pain or breathing difficulties then you need to seek urgent medical attention.
I hope you have a safe and comfortable flight.
Dr Makis
Dr Makis offers medical advice via his monthly article in the Paphos Post newspaper. If you require personal medical advice, contact your own GP in the first instance. For further information about Veramedica Medical Center, please contact us.