We believe it is a defect in the way the collagen is laid down in the vein wall, almost like a radial tire with a defect in the radial construction causing a blowout. Additionally, advancing age and added pressure due to obesity or standing still for long periods of time can make veins more vulnerable. Varicose veins are distinguished from spider veins by their rope-like appearance. Spider veins don't bulge under the skin but rather appear as red or purple squiggles, often in a web-like pattern. Since spider veins are caused by the same factors, their presence indicates an increased likelihood of developing varicose veins.
Spider veins and varicose veins are different forms of the same thing.
Like varicose veins, spider veins can form anywhere on the body, but are most common on the legs, where they can cause a dull, aching pain. Neighboring healthy veins then take over the function of the missing one. In Closure, a doctor inserts a catheter into a small incision behind the knee and, with ultrasound guidance, through the greater saphenous vein, which runs along the inner leg and is usually the source of varicosities. The catheter contains an electrode that emits radiofrequency energy inside the vein, causing it to heat, collapse and seal shut. Vnus Medical Technologies, the maker of the Closure device, says the procedure has been performed on around 1,000 patients in about 60 centers in the United States so far.