The risk of developing deep vein thrombosis as a result of long-haul flights has gained more attention in recent times following increased media coverage and community concern over the issue.

DVT is a common medical condition and occurs because of blood clotting, most frequently in the large veins of the calves. Sometimes these clots break free and travel up the veins through the heart to lodge in the arteries of the lungs. This related condition is known as pulmonary embolism (PE), which is a serious condition and can be fatal.

DVT occurs most frequently among people who are immobilised so it is not surprising that air travellers occasionally experience the condition of DVT, with some later developing PE.

While there are up to 400 deaths from PE in Australia every year, only a very small number appear to be associated with air travel. Immobility is the biggest risk factor and so long drives, and lengthy periods of being immobilised, for example following injury and illness, are times when consumers need to be aware of the risks

Many of the reported cases occur in association with identified risk factors for DVT which include increasing age, obesity, smoking, pregnancy, cancer, lower limb injury or surgery, family history of DVT, and previous thrombosis or embolism.

But air travellers can help protect themselves and the Australasian Society of Thrombosis and Haemostasis recommends that travellers drink plenty of non-alcoholic fluids during flights and regularly move their ankles and also massage their calves. The society also suggests wearing loose clothing.

Another way to help move blood is to wear compression stockings, which put gentle pressure on the leg muscles. Studies have shown that wearing compression stockings helps to minimise the risk of developing DVT after long flights and your community pharmacist may stock these products or may be able to source them for you.

Many airlines also have guides with information about DVT as well as in-flight exercises to help minimise the risk of DVT.

Being vigilant for the symptoms of DVT during and for up to a month after long flights is important. DVT symptoms include pain or tenderness in a leg (especially in the calf) or arm that gets worse with time, not better; swelling in one leg or arm; the skin of one leg or arm may become reddish or bluish in colour; one limb feels warm to the touch.

Before travelling, speak to your community pharmacist who can discuss the risk factors and also your personal situation taking into account any medical conditions you may have and any medicines you are taking.