What causes spider veins? part 2

Pregnancy: The one physiological condition where spider veins do become prominent is pregnancy. Many women develop spider veins on the face and lower thigh in the 2nd and 3rd trimester. This is linked to increased levels of estrogen, weight gain, and fluid retention. The increased fluid leads to engorgement of small veins that start to appear dark blue.

Estrogen is known to weaken walls of veins and also impairs function of valves which control blood flow. The increased fluid retention during pregnancy leads to stretching of the tiny veins that start to become more obvious.
Spider veins also become more prominent on lower legs and thigh during the 3rd trimester because the increased pressure from the fetus places pressure on the tiny veins. Often, these small veins rupture and appear as blue blotches. If a female has developed spider veins in the first pregnancy, she will likely develop more spider veins during subsequent pregnancies. Once pregnancy has ended, spider veins do lighten in color but do not always completely disappear.

Prolonged standing: Individuals who stand on their feet all day are prone to development of spider veins. The prolonged standing leads to pooling of blood in leg veins and this leads to engorgement of tiny veins. With standing, the leg muscles do not contract, hence blood does not move up to the heart. As pressure builds up, veins become more prominent and occasionally rupture and appear as bluish spots.

Prolonged sitting: Individuals who are in occupations where they sit all the time are also prone to development of spider veins. The prolonged sitting leads to muscle inactivity, blood pooling and engorgement of veins. Once you start to walk, muscles squeeze the excess blood which then starts to recirculate. Walking also drops pressure in the legs.