If an unnatural factor was the reason for varicose veins and thrombosis, why do not all people, who live with it develop such diseases?
200 years ago no man died of a car accident. Today in Germany 6000 people die every year in such a situation. Not all of the millions of car drivers die. And still car driving is the reason for the death of the 6000. Without a car none of them had died in a car accident.
It is an unnatural factor, which is causing an unnatural result.
The same is true with the primary wonder vein.