Treating Swelling at Its Source

Treatment for swelling starts with a question, not a product: what is causing it? This page follows that order.
The cause comes first
my.clevelandclinic.org ties treatment to cause. Edema treatments mainly depend on the cause. When your edema comes from an underlying condition, treating that condition may help.
On the Society for Vascular Surgery's site, a vein condition is described on its chronic venous insufficiency page, which is one place a reader can look while the cause is still open.
Treatment follows the cause
In sequence, then: find the cause, ask whether an underlying condition is involved, and discuss treating that condition. The source says treating it may help, and that wording is the honest limit.
Another condition on the list
Lymph flow is a separate question from vein flow. It is covered by the Society for Vascular Surgery on its lymphedema page.
Your list for the appointment
Note where the swelling sits, when it appears, and every condition you have already been diagnosed with.
The first thing to do
Read the MedlinePlus edema overview once, then take your list of conditions to the appointment.