Venous insufficiency happens if the veins while in the decreased extremities can't successfully force blood again to the center. This problem is often chronic in mother nature and arises if the leg veins turn out to be enlarged (identified as venous hypertension) as well as their valves can't shut correctly. https://www.sgvascularctr.com/swollen-leg-why-do-i-have-it-and-what-can-i-do/