How to prevent dvt on long flights/trips?

Stay mobile: Prolonged sitting, particularly with the knee in a flexed position, is a risk fctor for a deep vein thrombosis (dvt). Options to try to prevent this include getting up and walking around every 30 minutes or so, pumping your calf muscles up and down while sitting, trying to extend the knee as much as possible while sitting, and possibly taking an Aspirin product (which "thins" the blood).

Aspirin and Walking: If you do not have a reason you cannot take aspirin, an Aspirin prior to the trip might help, though has to be weighed against your risk of DVT vs. Bleeding. If you are in a car, take a break every hour or so to get out and walk around for a few minutes. In a plane, at least stretch your legs and flex your calfs a few times an hour. Compression stockings (15-30 mm hg pressure) also help.

Prevention: I would suggest getting up and walking around if on a long flight every hour. If on a long trip in the car also take several breaks during the trip. If you do need to sit for extended periods of time I would do calf raises multiple times which will help get the blood moving in the veins. I would also recommend the use of compression stockings during these long trips. Make sure to hydrate.

Dvt: Air travel related thrombosis is a real issue of concern due to immobility during airplane travel. The increased altitude, causes decrease in recirculation of the venous system. The best option for prevention is to use a support/compression stocking, and perhaps taking a baby aspirin prior to the airplane travel. Ankle pumping exercises-tip toe may also be of benefit.