Veins have valves. Vein valve leakage causes venous insufficiency(00) Save Image Image gallery: Venous Leak Causes
:max_bytes(150000):strip_icc()/venuous-insufficiency-overview-4177929-v1-5c3b9644c9e77c0001c7fd3a.png "Venuous Insufficiency: Symptoms, Causes, and Treatment")