Spider veins, so called because the “arms” of these tiny dilated blood vessels appear to project outward from a central denser area like the legs of a spider from its torso, are also called sunburst varicosities, for a similar reason, or telangiectasias (“broken” blood vessels). In fact, they are simply diminutive, thick venules (literally: little veins) that lie close to the surface of the skin. And because they principally carry deoxygenated blood (blood that is not saturated with oxygen needed by the tissues) they actually serve no useful function. Even nutrition-wise, it is the function of the the blood vessels hidden below the surface, within the dermis, that carry nutrients to the skin. In short, spider veins are just a plain, disfiguring nuisance.
The precise cause of these unwanted vessels is still the subject of investigation. However, we believe that they develop as a result of a complex interplay of genetic, hormonal and environmental factors. There is often a strong family history for their formation. You might find, for example, a mother, daughter and sister suffering the same problem. Elevated estrogen levels appear also to aggravate the problem. You might find that the condition worsens, for example,