Varicose veins are dilated tortuous veins with weakened walls and valves that no longer close when they should. They occur in the lower extremities and are important for the health of the skin and superficial tissues. They appear as bulges under the skin of the erect individual and disappear when the limb is elevated above the heart.
The valves inside the veins normally close in cycles when the blood flows through them or when pressure is applied from above. Their role is to prevent backflow (reflux) in the vein. Historically, these valves are of great importance because they were the critical clue (in 1628) that proved the circulation is designed to flow in one direction only. When valves fail to work properly the blood does flow back and forth in two directions and the vein no longer functions properly.
The pressure in lower extremity veins sustains high levels when an individual stands up and the valves fail to close (reflux). This reflux contributes to further weakening of the already abnormal vein wall and progressive enlargement of the veins occurs. Since refluxing veins do not conduct blood flow efficiently in the proper direction their value of returning blood to the heart is diminished and the circulation suffers; in fact, the circulation is actually improved when refluxing veins are eliminated.
The bulging of the walls gives rise to discomfort with aching and heaviness in some cases, or may be entirely free of symptoms in others. Whether they cause discomfort or not, varicose veins are sources of abnormal circulation in the skin and underlying tissue; over time this reflux may cause significant damage to the skin and tissues of the lower leg. The ultimate result can be swelling, discoloration, thickening, and even ulceration of the leg in up to 20% of long-term varicose vein cases.
Varicose veins development is a usually a slow process over time. The symptoms these veins cause are significant, but because the onset is gradual they are perceived as just normal aches and pains. It is not until the varicose veins are corrected that patients realize just how uncomfortable their legs have been. |