Diseases of the Veins
Three sets of vessels comprise the circulatory system: arteries, lymphatics, and veins. Arteries bring oxygen-carrying blood from the heart to the tissues. In the normal course of blood circulation, small amounts of fluid and protein leak from arteries and veins. Lymphatic vessels bring this protein-rich fluid back into the circulation. The third type of blood vessel is the vein.
Veins bring oxygen-depleted blood from the organs and tissues to the heart and lungs, where it is re-oxygenated. Blood return to the heart tends to be passive and is enabled by muscle contraction in the arms and legs. Because the venous system is a low pressure one, the telltale complaints and physical signs of venous disease on which your physician relies for diagnosis are often subtle and sometimes require further testing. Diseases of the veins fall into two broad categories: blockage from a blood clot (thrombosis) and inadequate venous drainage (insufficiency).
The legs are the most common location for blood clot formation (thrombus) in the venous system. Today, the most commonly encountered causes for blood clots include cancer, prolonged immobility, an inherited tendency for blood clotting, pregnancy, and contraceptive use.
Blood clots may develop in the veins that lie either just under the skin or deep within the limb. In the skin-deep (superficial) veins, a blood clot commonly appears as a red streak along the course of an affected vein and is often accompanied by inflammation (phlebitis). The vein may feel warm and tender and may be swollen. This combination of clot and inflammation, known as superficial thrombophlebitis, commonly occurs in the setting of varicose veins. Cancer may be the cause for development of many episodes of superficial blood clots; this is known as Trousseau’s syndrome.
Superficial thrombophlebitis is typically more annoying than dangerous because the likelihood that the clot(s) will …