20-30 mmHg or 30-40 mmHg compression stockings?

my Dr. recommended the 20-30mmHg and they work ok but if I don't wear them on the weekend as well by Monday morning there's swelling again. is this run of the mill? what's the difference between the compression sizes? would the 30-40mmHg work better?

Answers: The 30-40 mmhg will be tighter.