There are ways to prevent travel-induced DVT. First, drink water for hydration. Very important! In the same way, avoid alcohol to avoid DEhydration. Don't take sedatives or sleeping tablets b/c you'll want to be mobile during the flight. Also consider wearing compression stockings. Finally, ask your doctor if you should take anticoagulant medication.
Here are some exercises you'll find helpful for your calf and foot muscles. Practice these before, during and after the flight (and regularly).
* Take a walk up and down the aisle every hour or so, when the aircraft crew say it is safe to do so.
* Every half hour or so, bend and straighten your legs, feet and toes when you are seated.
* Press the balls of your feet down hard against the floor to increase blood flow.
* Walk slowly but surely to and from the gate when you depart and arrive.