Depends what the "cause" is

Work on your feet all day or Diabetic Neuropathy or some other vascular issue, infection or something else

It's really tough to figure out "what to do" until you figure out the cause - the remedies for each can be quite different

Diabetic Neuropathy is the "the most common" diabetic complication affecting 1 in 2 diabetics during the course of the disease

It is caused by years of "a little bit high" blood sugars that damage the small blood vessels, primarily in the extremities, with the feet and lower legs being the most common

The damage to the tiny blood vessels causes the nerves to become irritated, damaged and then die

The symptoms (early stage) start out with possibly numbness, tingling, feeling hot and as it progresses it can become extremely painful, result in infections and necrotic tissue which can lead to significant infection, gangrene and ultimately, amputation of the dead/infected (part) - not somewhere you want to end up

Having your feet swell from simply sitting long periods "could be" anything from something as harmless as "edema", a common condition that is not dangerous that results simply from sitting still too long (we need to move to force circulation to the feet - or you can elevate them which will clear the problem if it's edema) all the way up to an indicator of Congestive Heart Failure where the heart is just not strong enough to get sufficient blood flow all the way to the feet

Of course there is dozens of other potential reasons which is why you really need to get a professional, who understands your entire health picture, to try and determine the cause

Each potential treatment, depending on the cause, could be quite different and you don't want to get it wrong - the potential consequence of misdiagnosing could result in a life altering outcome

If it is Diabetic Neuropathy you may be able to halt it but unlikely dial it back, so if it is it needs to be identified and you need to be told what needs to be done if you want to prevent it from getting worse (as one example)

What is diabetic neuropathy? I have recently been having swollen feet when I sit longer than an hour? What could this mean or what could cause it?