This is virtually the only "commonly known" fact about varicose veins that does appear to be true.

Varicose veins do run in families.

However - the link is not quite as strong as most people like to believe.

For example, although having 3 or 4 relatives with varicose veins or venous problems makes it more likely that you will too - but doesn't mean that you definitely will. Also, the fact that you have varicose veins does not mean to say that all of your children will have too - although they will be more likely to than most other children.