To thrust blood back to the coronary heart, your veins count predominantly on bordering muscles and a community of one-way valves. As blood flows through a vein, the cup-like valves open up to allow blood via, then close to circumvent backflow. Weak or broken valves can cause varicose veins. Arteries have blood from https://www.sgvascularctr.com/varicose-veins-explained/