The flow of blood leaving your legs is rather sluggish when you’re stuck motionless in a seat during air travel. It tends to encourage an accumulation of fluid in your feet (gravitational edema). Ordinarily, the muscles of the leg, and particularly the calf, act as pumps to encourage the main veins in the leg to empty upwards. Just walking does most of the work in this respect.

To minimize the problem during air travel, it is suggested that you keep your feet moving, constantly stretch and flex your calf muscles, get up and walk about the airplane every half an hour or so.

An additional option would be to wear support stockings for the duration of the flight. It is best to use an above-knee stocking that has been measured to fit properly. There are a few folk who should not use support stockings. They tend to be older people with poor arterial blood supply to the legs.

If, however, you are getting swollen legs in your everyday life, then that is something you need to discuss with your own doctor so that it can be investigated further. I hope this helps.