If you are going on a long-haul flight, deep vein thrombois (DVT) is a potential worry. DVT is also called 'economy class syndrome', although you can get it no matter what class you fly in.
DVT is when a blood clot forms in the deep veins of the leg which, if it doesn't disperse, it can move up into the lungs. This can be fatal, and has been linked to flying.
The trouble is, on a long haul flight you can't move about on a plane very much, which means that there is some chance of a clot forming. This risk can be increased by the dehydration flying often causes, by drinking too much alcohol or coffee and by sleeping in an awkward position.
You can help reduce the risk of developing deep vein thrombosis by: