Hiya sushi

Firstly I would check with your Gp in case there is some underlying problem. Otherwise, make sure you are drinking enough fluids daily - the danger is cutting down when you are swollen- and doing plenty of exercise, preferably walking - and perhaps consider taking a "water" tablet like aquaban.

If the swelling happens when sitting down - ie flying, coach travel etc, make sure you move about plus do some ankle exercises.

Hope the above helps