If you sit a lot during the day and your legs swell but the swelling goes down overnight try these suggestions.
When you are stuck at the desk do the same thing that is recommended during air travel:
I call them ‘butt-ups.’ Squeeze your buttocks; make the buttock muscles tight so that you get pushed up.
If you did this several times, you would look like you are bouncing. Do it several times in a row.
The muscle contractions get the blood and lymph fluid moving. You can do this with large or small squeezes. You can also alternate sides–left, right.
Also, to help reduce the swelling in your legs, at other times, lift one foot and rotate the ankle several times. Alternate legs and directions. Also do toe lifts (lift your toes toward your knee.)
If you are able to stand for a few minutes, do a couple of toe raises. And lift a leg behind you. Lift one leg at a time behind your body to stretch out the front side.
You should have enough room beneath your chair seat and your thighs so that you can slide your fingers between seat and thigh. That way there is no pressure on your thighs. Sit on your sit bones.
But you don’t want to have too much bend in your knees, either. The solution may require some trial on your part. Sometimes sliding the feet forward a bit helps. Or maybe you can create a seat with a downward tilt to it by placing a folded towel on the seat and see whether that helps?
Or maybe lots more standing breaks?
http://www.simplestrengthening.com/2008/03/30/legs-feeling-weak-or-achey-how-balancing-can-help-your-legs-get-stronger/
That link will take you to an article about how to balance on one foot. That uses ALL the muscles in your leg and so squeezes the blood and lymph vessels to keep the fluid moving.
Also, if you notice that you are leaning forward in your chair to do your reports or desk work, strive to sit more upright and create less angle between your thighs and abdomen. Maybe you can pull your chair in closer to the desk? Or pull your monitor closer to you.
There are all of these various issues that we have to adapt to as we get older like vision issues, etc., but sometimes making little adjustments or adaptations can make a big difference in our comfort and in our future comfort. That’s why you want to take steps now to reduce that work-day swelling–to keep your blood vessels healthy and flexible.
And here’s the overall picture of how we want to be: Strong back side but soft calves, head over our shoulders rather than in front, breastbone raised.
And walk! Walking is excellent for legs.
I hope these steps will help you start getting rid of the swelling in your legs soon.