Why have I got thread veins?

Exactly what happens in the body to produce thread veins is not known for sure. Women develop spider veins nearly four times as frequently as men. About 70 percent of adult women are afflicted with spider veins at some time in their lives. Spider veins appear to be hormonally induced and often are associated with pregnancy and use of the oral contraceptive pill. Although these spider veins do not produce symptoms, the feeder veins deeper in the skin may cause discomfort. The risk factors for spider veins include: