Persistent venous insufficiency. Leg swelling (oedema / drinking water retention) associated with chronic venous insufficiency is quite common. It accounts for 90% of your situations of leg swelling. It is commonly seen in patients with long-standing varicose veins, former historical past of deep vein thrombosis and iliac (pelvis) vein compression. https://sgvasculargrp.com/medical-condition/lymphoedema/