Venous System and Vein Disease Overview

The venous system effectively pumps blood out of the legs against gravity unless the valves become incompetent and fail to function normally. Whether in the superficial or deeper veins, incompetent valves produce a reversal in vein blood flow, moving blood back towards the feet when the legs are at rest. The inability of the venous system to drain properly produces increased blood pressure (venous hypertension) in the affected blood vessels that expand or dilate to accommodate the enlarged blood volume.

As vein disease progresses, larger veins dilate and become varicose veins. These distended veins can put pressure on nerves causing aching pain, night cramps, restless legs, itchy skin, and unusual sensations on the legs. Distended veins can leak fluid into the surrounding tissues resulting in swelling or edema. A brownish skin discoloration on the skin around the ankle and lower tibial area called hemosiderosis can result from a leakage of the products of blood cell breakdown into these tissues. Venous hypertension also affects the ability of blood to flow across capillary beds, disrupting the exchange of oxygen, nutrients and cellular wastes. The tissues of the leg respond first by thickening and finally by dying. The ultimate consequence of vein disease is a venous stasis leg ulcer with infection of the surrounding skin called cellulitis.

Many factors including heredity, inactivity, advancing age, and occupations requiring prolonged standing can all be contributing factors for diseases of the veins. Other common predisposing factors are obesity, pregnancy, prior episodes of blood clot formation, trauma, illness, surgery, medication and sedentary lifestyle. During pregnancy, a large increase in blood volume causes veins to enlarge. This combined with pressure on the veins from the growing uterus results in spider and varicose vein formation. Varicose veins generally improve within 3 months after delivery.