I found this out the hard way. I was what turned out to be on my final deployment. Two flights and a bus ride to the base later I was having trouble putting weight on my left leg. When I got back I found out I had two bloodclots or DVTs. They messed up my veins. There is no way to reverse it.
Since then I've had bilateral DVTs and PEs. As of last month, I had a deep brain stroke.
WEAR THE SOCKS.
Walk around if you can. Even if it's just up and down the aisle.