All reputable airlines and holiday companies provide information on DVT and you are strongly recommended to seek advice if you are the type of passenger who is most likely to be affected by the condition and how to reduce the risks when flying.
Most passengers can reduce the risk of DVT and the consequent sudden death through keeping circulation active by practising in-seat exercises, particularly leg exercises, whilst aboard the airplane. Most airlines and holiday companies also advocate walking around the aircraft to reduce the risk but any regular air travellers will know this is not always practical or even possible.
Most airlines will provide details of exercises you can do in their in-flight magazine or during the in-flight videos. However, to give you an insight to what they are and perhaps even to give you a chance to practise them before you fly here are some of them.
1. During the flight place a pillow in the hole of your lower back to maintain the curve of your spine. Avoid crossing your legs. This will help your back as well as your blood circulation. Try to keep your weight evenly balanced on each buttock and keep your shoulders relaxed.
2. Sit back in your seat and flatten the head rest. Sitting up straight and with your shoulders relaxed allow your head to roll slowly to one side. Then, gently roll back through its central position to the other side. Repeat this exercise several times.
3. Sit upright in your seat and move forward a little. Lift your shoulders up towards your ears and then circle them back down. To help you with this exercise imagine you have pencils on the tips of your shoulders to draw circles. Repeat this exercise six times. Then lift your shoulders up towards your ears and drop again. Repeat six times.