My husband and I get edema in our feet, lower leg area and hands from time to time and have found that wearing compression / firm support long socks help with the discomfort in addition to increasing our water intake and decreasing our salt intake.  What we've found however is that some brands of compression or firm support socks are SO tight that they are incredibly difficult to put on and remove after washing & drying several times - even if we order the correct sizing.

My husband really likes this Dr. Scholl's Men's Microfiber Firm Support socks because they weren't quite the uncomfortable compression type socks yet provided firm enough support to help with the discomfort and swelling from edema in his feet, ankles and calves and after now using these for a couple of months, they have held up beautifully! No snagging, no pilling - unlike some other socks, they have held their shape, don't roll down and are still comfortable without being too tight.  If you prefer the extremely tight compression / firm support clothing, this may not be for you but this level of firmness is what we think is perfect for our needs.