Good question.
It may sound very strange to you but it could be linked to your bowel habits. Straining causes high pressures and will damage the valves, causing varicose veins.
For more details view this article by John McDougall
http://www.drmcdougall.com/health/education/health-science/common-health-problems/constipation-hemorrhoids-varicose-veins/
That is strange. And thank u for the info.
Varicose veins are the result of the one-way valves within the vein breaking down allowing the blood to pool. The difference between larger varicosities and smaller (spider) varicosities is the actual size of the vein. Spiders are the offspring of a larger vein. If you need more info., like treatments available let me know. jd1963