Is it possible to give yourself varicose veins by standing for one very prolonged time?

Standing and VV. Blood is returned to the heart through the leg veins. in order to do this the calf muscles must contract and the venous valves must work to push the blood back up the leg. Prolonged standing can lead to loss of the pumping action of the calf muscles which can lead to increased venous pressure which can lead to varicose veins. Wear support hose if standing for long periods of time.
Hereditary veins. Vein disease is inherited and factors such as prolonged standing, prolonged sitting, heat, weight lifting, hormones, pregnancies etc aggravate the disorder. Sometimes the valves inside the veins get weak over time causing reflux- a backward flow of blood down the legs and this pressure can dilate the vessel wall. It seems sudden, but it has been happening over time. Go to www.Morrisonvein.Org.
Possibly. The number one link to varicose veins is family history. Other things can be number of pregnancies, some jobs, age and some studies show being over-weight.
It is possible. Some studies have shown that prolonged standing can increase comeone's risk of developing varicose veins. As others have said, the main risk factor is heredity. You can't cahnge that but you can improve the situation at work if you have to stand all day. Wearing proper fitting 30-40 mm hg knee high compression stockings (not ted hose) every day has been shown to make a difference.
Maybe. Varicose vein occurs when blood is pooled into the veins because of gravity and/or damages to the valves within the veins that prevent the blood to back flow , thus people who stand or seat a lot may develop varicose veins if they have incompetent valves within the veins of their lower extremities, they may also develop hemorrhoids.