Spider veins, also known as telangiectasias, are the visible purple/blue veins seenon the surface of the skin. Spider veins are not essential to normal function. A number of factors contribute to the development of spider veins including heredity/genetics, pregnancy, hormonal shifts and occupations or activities that require prolonged standing or sitting. It is estimated that nearly half of adult women in the United States have spider veins. Men also get spider veins. Patients seek treatment of spider veins because they do not like their appearance or because spider veins can cause symptoms such as aching and throbbing.