Varicose Veins: Etiology

00:00 So let’s talk a little bit about what are the mechanisms that lead to varicose veins.

00:06 Prolonged standing does it because, of course, gravity increases the pressure in the veins in the legs. And that’s the same reason that long aeroplane flights can also result in swelling in the legs and even deep venous thrombosis because of what is known as stasis – that is increased pressure that holds the blood in the vein at a higher pressure and actually results in fluid being squeezed out of the capillaries.

00:35 The same thing happens, as I’ve said before, in pregnancy where there’s increased intra-abdominal pressure. The uterus shown in this little cartoon actually can sit on the veins, particularly as the fetus gets larger, and result in poor drainage of the veins from the leg.

00:56 Defective venous valves are probably an inherited tendency. If the valves don’t work, then this impairs the ability of the blood to travel back to the heart from the veins results in dilatation of the veins and further damage to the wall.

01:15 There are hormonal effects, particularly estrogen effects. Again, referring to pregnancy or with contraceptive pills, that can result in some venous dilation that can predispose.

01:28 Heavy lifting, when one grunts and strains to lift, there is a marked increase in pressure in the venous system. And with repeated heavy lifting, this repetitive increase in the pressure in the vein can result in dilation and varicose veins.

01:43 And, similarly, obesity reduces the support of the superficial tissues to hold the veins in place and they can dilate. And of course, also with obesity, there’s increased intra-abdominal pressure and that also increases the pressure in the veins and can result in dilation of the walls and failure of the valves to function.