Bicuspid (Butterfly) valves that back flex due to genetic deficiencies (they grow wrong) can do it, leading to a small reverse flow of blood in the veins/arteries at valve junctions. My dad had it, so do I.
Is it related to more than valvular anomalies?
Veins have valves, but arteries do not.
I'm just curious what's causing the unusual dilatation to your venous AND arterial systems.
In my mind, conditions and pathologies affect them independently.