Chronic venous insufficiency
Chronic venous insufficiency (CVI) is a medical condition characterized by blood pooling in the veins, leading to increased pressure and strain on the vein walls. This is most commonly caused by blood flowing backwards in veins near the surface due to faulty valves, which can also result in the formation of varicose veins, a treatable condition.
Source: Wikipedia — Chronic venous insufficiency (CC BY-SA 4.0)