Causes of Spider Veins
The exact cause of spider veins is unknown, although heredity, pregnancy, trauma, aging, sun damage and hormonal influences are believed to be primary factors contributing to the condition. More than 40 percent of women have some form of varicose vein condition including spider veins, with an increasing incidence of venous disease as one gets older, so that up to 80 percent of women have some form of venous disease by age 80. Slightly more women than men have varicose and spider veins.