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