Chronic Venous Insufficiency
Chronic venous insufficiency (CVI) is a common cause of leg pain and swelling, and is commonly associated with varicose veins. It occurs when the valves of the veins do not function properly, and the circulation of blood in the leg veins is impaired. CVI may affect up to 20 percent of adults. CVI can be caused by damaged valves in the veins or vein blockage. Both may be a result of deep vein thrombosis (DVT) or blood clots in the deep veins of the legs. If a clot forms in the superficial veins, there is a very low risk of DVT occurring. Over time, CVI may result in varicose veins, swelling and discoloration of the legs, itching and the development of ulcers near the ankles. Vein problems are among the most common chronic conditions in North America. In fact, more people lose work time from vein disorders than from artery disease. By the age of 50, nearly 40 percent of women and 20 percent of men have significant leg vein problems. Spider veins occur much more frequently in women. It is estimated that at least 20 to 25 million Americans have varicose veins.
Veins are the soft, thin-walled tubes that return blood from the arms and legs to the heart. Because veins work against the force of gravity, they have valves that allow forward blood flow, but not reverse. Your legs and arms have two major types of veins: superficial and deep. The superficial veins are near the surface of the skin and are often visible. The deep veins are located near the bones and are surrounded by muscle. Connecting the deep and superficial veins is a third type of vein, the perforator vein. Contraction (squeezing) of the muscles in the arms and legs with exercise helps blood flow in the veins.
Varicose veins are enlarged, bulging superficial veins that can be felt beneath the skin, generally larger than 3-mm in diameter. They are usually located on the inside of the calf or thigh and develop due to weakness of the vein wall and loss of valve function. Under the pressure of gravity, they continue to enlarge, and in the course of time, they may become elongated, twisted, pouched and thickened.
Spider veins or telangiectasia are tiny dilated, veins, usually less than 1-mm in diameter, located at the surface skin layers. Spider veins cannot be felt. Veins larger than the spider veins, but still under 3-mm are called reticular veins.