What are varicose veins?
Varicose veins--which afflict 10% to 20% of all adults --are swollen,
twisted, blue veins that are close to the surface of the skin. Because
valves in them are damaged, they hold more blood at higher pressure
than normal. That forces fluid into the surrounding tissue, making the
affected leg swell and feel heavy.
Unsightly and uncomfortable, varicose leg veins can promote swelling in the ankles and feet and itching of the skin. They may occur in almost any part of the leg but are most often seen in the back of the calf or on the inside of the leg between the groin and the ankle. Left untreated, patient symptoms are likely to worsen with some possibly leading to venous ulceration.
What causes varicose veins?
The normal function of leg veins - both the deep veins in the leg and
the superficial veins - is to carry blood back to the heart. During
walking, for instance, the calf muscle acts as a pump, contracting veins
and forcing blood back to the heart.
To prevent blood from flowing in the wrong direction, veins have numerous valves. If the valves fail (a cause of venous reflux), blood flows back into superficial veins and back down the leg. This results in veins enlarging and becoming varicose. The process is like blowing air into a balloon without letting the air flow out again- the balloon swells.
To succeed, treatment must stop this reverse flow at the highest site or sites of valve failure. In the legs, veins close to the surface of the skin drain into larger veins, such as the saphenous vein, which run up to the groin. Damaged valves in the saphenous vein are often the cause of reversed blood flow back down into the surface veins.
Why does it occur more in the legs?
Gravity is the culprit. The distance from the feet to the heart is
the furthest blood has to travel in the body. Consequently, those vessels
experience a great deal of pressure. If vein valves can't handle it,
the backflow of blood can cause the surface veins to become swollen
and distorted.
Who is at risk for varicose veins?
Conditions contributing to varicose veins include genetics, obesity,
pregnancy, hormonal changes at menopause, work or hobbies requiring
extended standing, and past vein diseases such as thrombophlebitis (i.e.
inflammation of a vein as a blood clot forms.) Women suffer from varicose
veins more than men, and the incidence increases to 50% of people over
age 50.
