What is Venous Insufficiency

Venous insufficiency is the inability or difficulty of the leg veins to return blood back to the heart. As the blood pools in the leg it leads to heaviness and swelling at the end of the day and over time it may gradually progress to spider veins, varicose veins and even skin discoloration and ulcers at advanced stages.

Varicose veins are enlarged veins that are visible through the skin and may appear as blue or purple twisted, knot-like cords on the leg.

Varicose veins

Spider veins, a milder type of varicose veins, are smaller than varicose veins and often look like a sunburst or "spider web." They are red or blue in color and are commonly found on the legs, just under the surface of the skin.

Vein Anatomy and Venous Insufficiency:

Veins should not be confused with arteries. The arterial system directs blood flow (rich in oxygen) from the heart to the body while the venous system returns blood (poor in oxygen as it has been consumed) back to the heart. Have you noticed that medical illustrations indicate the blood vessels red and/or blue? The red blood vessels represent the arteries, the blue ones represent the veins. This simulates reality as indeed high oxygen levels in the arterial blood give it a bright red color, while low oxygen levels in the venous blood make it look dark blue.

Our legs have two distinct systems of veins: superficial and deep. The superficial system is made up of veins that are close to the skin, the major ones known as "great saphenous vein" (inner side of the thigh and lower leg) and "small saphenous vein" (back side of the calf). The deep system is comprised of larger veins deep within the muscles of the leg. The two systems are connected by small communicating (perforator) veins. All veins eventually merge to form the big central veins in the abdomen and chest. Venous return to the heart occurs predominately through the deep veins and this is of particular importance as when the superficial veins are diseased (e.g. varicose veins) they can be removed without disturbing the venous circulation since it is then deviated through the deep veins.

Normal venous valve function and venous insufficiency

A major difference of the veins compared to the arteries is that veins have one-way valves. Arteries do not need valves as the blood flow is maintained by the pressure generated by the heart pumping. Blood pressure in the veins is lower than that of the arteries and valves facilitate blood flow (e.g. maintaining flow "upwards" against the gravity). When the leg muscles contract they squeeze the deep veins and the valves open. When the leg muscles relax the valves close preventing blood from flowing backward. When the one-way valves become weakened or damaged, blood flows backward and pools in the veins, stretching them as a result of increased pressure. This stretching of the veins weakens further the walls of the veins and damages even more the valves. This is called venous insufficiency. Spider veins or thick varicose veins may subsequently result.

Risk Factors of Venous Insufficiency:

There are a variety of risk factors that contribute to the development of venous insufficiency, varicose veins or spider veins:

• Inactivity, sitting or standing for long periods: the leg muscles do not contract to pump blood upwards and pressure in the veins increases.
• Obesity: excessive weight increases the pressure in the veins of the legs and aggravates the condition.
• Aging: varicose veins usually affect people between the ages of 30 and 70. With advancing age, the elastic shell of the vein begins to weaken, increasing the chance that the vein will dilate.
• Female gender: women are particularly susceptible to venous insufficiency because of the influence of progesterone on the veins and the effects of pregnancy. Women are 2-3 times more likely to have varicose veins.
• Pregnancy: pregnant women have an increased risk of developing varicose veins due to the hormonal influences of pregnancy on the veins but also due to compression of the central veins by the enlarging uterus that increasing the venous pressure in the leg veins. The veins often return to normal within one year of childbirth. Women who have multiple pregnancies may develop permanent varicose veins.
• Leg injury: veins can get injured and damaged.
• Smoking: increases the risk of venous thrombosis which subsequently destroys the valves.
• Deep venous thrombosis: When the deep main veins of the leg get blocked or damaged by a clot the blood flow is deviated through the superficial venous network. As the superficial veins receive higher blood volume and pressure they eventually dilate to form varicose veins.
• Pelvic mass: rarely a pelvic mass (benign or malignant tumor) may compress the central veins obstructing the blood outflow of the legs, thus increasing the venous pressure in the leg veins.
• Family history.

Although these risk factors increase a person's risk, they do not necessarily cause the disease. Some people with one or more risk factors never develop the disease, while others develop disease and have no known risk factors, indicating the effect of the genes (family history). Knowing your risk factors to any disease can guide you into the appropriate actions, including changing behaviors and being clinically monitored for the disease.