Veins return blood from the rest of the human body to the heart. To return blood to the guts, the veins while in the legs should operate towards gravity. Weakened valves, also called incompetent valves, inside the veins may cause varicose veins. النزيف. في حالات نادرة، تنفجر الأوردة القريبة من https://www.sgvascularctr.com/varicose-vein-treatment-in-singapore-answers-to-your-most-common-questions/