What is the cause of varicose and spider veins?
he cause of spider veins is not known, although they tend to run in families and occur more often in women. Female hormones or pregnancy are often a factor. Increased blood pressure causes even the smallest veins to swell, but you can be perfectly healthy and have spider veins as well. Spider veins can also be caused by injury or clothing that is too tight. They are not caused by standing, but standing for long periods of time can make them worse.
