Varicose veins are permanently dilated, twisted veins caused by reverse blood flow due to incompetent valves. They commonly occur in the legs and can cause pain, heaviness, and leg swelling. The document describes the anatomy of leg veins and perforating veins that connect deep and superficial veins. Risk factors for varicose veins include prolonged standing, obesity, and female sex hormones. Treatment options include compression stockings, sclerotherapy to scar and close veins, and surgical procedures to remove or close off damaged veins. Endovenous laser ablation is a minimally invasive surgical technique to treat varicose veins.