The corrupted feedback hypothesis.

This paper argues that varicose veins are caused by a feedback malfunction. The feedback in question regulates the tone of the vein by dilating it as needed, using noradrenaline (NA), tapped from the circulating pool, for the purpose. The drug, though conventionally classified as a venoconstrictor, dilates the vein when it diffuses from the vasa venarum of the vein into the vein's media; the drug having reached the vasa by reflux from the vein lumen. A varicosity is created when a factor increases the volume of reflux, and, therefore, the quantity of NA, perfusing a unit of the vasa network, selectively. The resultant, exaggerated, localised, dilator effect that the NA has on a section of the vein, constitutes the varicosity radix. In brief, a varicosity, when first created, is seen as being an exaggerated, but appropriate, dilator response of a section of a normal vein to an inappropriate, corrupted, feedback signal. The acute varicosity is believed to transform into the permanent type seen in varicose veins if the factor responsible for it persists long enough.