Disorders of the valves may affect the veins of the superficial, the perforating, or the deep systems. Often, they occur in combination. The character and severity of symptoms will depend on which of these systems is predominantly affected.
Small blemishes in the skin can be dilations of the minute branches of veins. They have a red or blue appearance. Because the dilations often radiate from a central venule, they are commonly referred to as “spider veins.”
Spider veins are of concern mainly as a cosmetic issue. When large, however, they can cause itching, burning, pain, or swelling in addition to unsightliness. Spider veins are more prevalent in women. Their size and associated symptoms tend to be worse during menstruation, ovulation, or pregnancy, suggesting the influence of a hormone (most especially progesterone). They can be obliterated with injections of a sclerosing agent administered through a fine needle.
The tiny veins in the skin have no valves. When dilated to form spider veins, venous reflux is not involved in most cases, and there is no known cause. Their appearance can occur without underlying venous disease. They are more prevalent, however, under the stress of reflux valves from a nearby varicose vein. Multiple spider veins are common.
Clusters of cutaneous veins that are more extensive than spider veins are called “telangiectasias.” They are localized blotches that can appear on any part of the body but most frequently occur on the back of the calf and over the outer thigh. Like spider veins, they can occur without underlying venous valvular disease but are much more common where valvular defects occur.
Two examples of telangiectasias are shown to emphasize the wide difference in their appearances.
The superficial veins lie just beneath the skin. One important function is to serve as radiator by dissipating heat into the external environment. When the body becomes overheated, the superficial veins dilate to expose more blood to the body surface. In a cold environment, the superficial veins contract to conserve body heat. This reactivity is most striking in the face as well as in the hands and feet.
Reflux of blood in damaged or absent valves in the superficial leg veins may cause permanent widening of the veins, a condition known as varicose veins. Ubiquitous in the population, varicose veins are saccular dilations which tend to follow a tortuous course. They can involve the greater saphenous vein (extending from the ankle along the ...