My mother and my sister both have varicose veins. I have the spider veins (smaller, reddish version). Though my previous occupations involved standing/sitting for long periods of time, and now, being a stay-at-home mom, I still do the same when working in my kitchen, or in front of my computer, I still have prevented acquiring those big, unsightly varicose veins despite a strong history.
How to prevent developing them? As what I used to practice with my patients (I was a general practitioner) when I was in the Philippines, I inform them first, explain the pathophysiology of an illness/condition, before proceeding with the approach of management. That was preventive medicine, which is, to me, the level of health care most often ignored by patients, but from which they would benefit most.
So what are varicose veins? These are superficial (as in underneath the skin) veins dilated (enlarged) because of poor circulation of blood, as what happens during prolonged standing and sitting. In some cases, when the blood pools it encourages clotting.
What exactly do we mean by poor circulation? Understand first that we have arteries that pump oxygenated blood away from the heart, and veins that pump unoxeygenated blood back to the heart, mediated by the capillaries.
Veins are less elastic than arteries, and have less pressure. While the arteries can squirt blood as a result of its elastic recoil brought forth by the cardiac output (the volumeof blood that comes out of the heart with every pump), the veins, on the other hand, have less resistance (they don't need it anyway, because at the capillary level, before blood from the tissues is passed on to the veins, there is minimal resistance...only a gentle stream of blood). What they have are valves, that work in such as way as follows:
Every volume of blood added to the veins with every pump of the heart, the veins receive and gradually pump(through the areterial push) back to the heart. For the leg veins, this is hard because of the gravity tending to pull the blood down. Veins have valves that prevent this volume to go back down and pool. However, for the superficial veins in the legs, the burden is severe, thus the tendency for the blood to pool. If pooled blood is enough to stretch the walls of the veins, the valves do not close properly, resulting to more backflow, more stretching, possible blood clotting -- the veins now become so unsightly, like worms.
So to prevent this formation, we must help pump the blood up. How? Move your calf muscles (or simply, your legs) during prolonged standing/sitting. How this helps?
Since the superficial veins are connected to the deep veins (embedded in the muscles), moving these muscles will squeeze the venous blood, pumping it up back to the heart. The vaccum created in these deep veins suck the blood in the superficial veins, thereby helping in continuous flow of blood from the arterial end to the heart.
Those of you who have experienced waiting long for a jeepney for vacant seats, ever noticed how your calf muscles ached, and actually got more relief if you just tried walking while waiting instead of just standing? The relief was because of this unloading of leg veins, in exchange for tired muscles, which to me is healthier than developing varicose veins, in that you develop tone in your leg muscles, and burning more calories. (Although the pollution in Metro Manila is not healthy at all.)