The underlying cause for varicose veins, advanced enough to need varicose vein treatment, is a condition called chronic venous insufficiency (CVI). While some people claim that varicose veins causes CVI, the reverse is usually true, although the development of varicose veins often worsens chronic venous insufficiency without the intervention of varicose vein treatment.
What Is Chronic Venous Insufficiency (CVI)?
Simply put, chronic venous insufficiency (CVI) occurs when the body has trouble returning blood from the lower extremities back to the heart. In more practical terms, CVI is a disease that involves malfunctions in the one-way valves in the veins. You can think of CVI as the veins being “insufficient” to do their jobs due to the destruction or impairment of the one-way vein valves.
When they are working properly, one-way vein valves an engineering marvel! They consist of two flaps of tissue (bicuspid) that “swing open” to allow blood to flow against gravity back to the heart and then close and meet in the middle of the vein to prevent the back flow of blood. These bicuspid vein valves help your veins defy the gripping force of gravity and the sluggish and variable speed of blood flow in the veins.
Why Do Veins Have Valves But Arteries Don’t?
Okay, now that you know that veins are not just one continuous tube with blood flowing through them. Instead, veins have valves that are located along the length of a vein “tube” to ensure that blood doesn’t flow backwards. Now, the question becomes, “Why don’t arteries have valves too?” The basic answer is that arteries don’t need valves because the pressure is so strong in them, there is little chance of any back flowing of blood. This is also why we don’t get “varicose arteries.”
The heart is the strongest muscle in the body, and when it pumps blood out through the arteries, it does so with a powerful strength. As blood leaves the heart, it moves through the arteries with such force, there’s no chance that blood will slow down too much, back up, and pool in the arteries. It’s not until the blood has gone through the capillaries and entered the veins that the blood velocity has slowed down so much that it may even stop. This much lower blood pressure in the veins versus the much higher blood pressure in the arteries that make vein valves necessary. Remember too, that blood in the veins is going “uphill” against gravity.
What Causes Chronic Venous Insufficiency (CVI)?
The most common cause of CVI is deep vein thrombosis (DVT). This is a blood clot in one of the deep veins, i.e. a vein buried in the muscles of the leg. When there is a thrombosis (clot) in a deep vein in the leg, it interferes with the flow of blood in the vein and this causes the blood to pool rather than return back to the heart as it normally would. In superficial veins close to the skin, varicose veins are the most common cause of CVI, although varicose veins may stem from something happening deeper down. When this happens, varicose vein treatment is often needed to overcome the impairment and the painful symptoms of varicose veins near the surface of the skin.
Weak leg muscles, especially weak calf muscles, sometimes contribute to chronic venous insufficiency since the leg muscles help squeeze (pump) the blood in the veins running through them back to the heart. Of course, increasing your exercise can help eliminate this factor to CVI. In rare cases, cancer of the pelvis can block normal blood flow in veins and cause CVI in the legs.
In other rare cases, abnormalities in the venous structure, sometimes from birth, can cause CVI or put one at higher risk for developing CVU and needing varicose vein treatment. If you go in for a duplex ultrasound (Doppler Ultrasound) at Metro Vein Ceners, you’ll actually be able to view the inside of your veins and vein valves in 3D graphic relief! Just ask your technician or doctor to show you your vein valves.
In 1999, a paper entitled, “Number of Valves in Superficial Veins of the Leg,” was published in Folia Morphologica, a journal of the Polish Anatomical Society. In this paper, researchers demonstrated a great variability between people in the number of one-way valves in the saphenous veins of their legs. In the great saphenous vein, they found that people had between three to thirteen valves. In the small saphenous vein, people had between one and eight one-way valves. It would stand to reason that a person with more vein valves would have a lower risk of developing CVI than a person with fewer vein valves. This variability in the number of vein valves in the saphenous vein may help explain the genetic component of varicose veins and people needing varicose vein treatment.
Of course, all of the causes of CVI have a strong genetic component but they’re also all interrelated. If your parents, aunts, or uncles have CVI, you will have a much higher chance of getting CVI and developing varicose veins. Likewise, if one or more of your relatives is a candidate for varicose vein treatment, chances are much higher than average that you will also need varicose vein treatment in your lifetime. If this is true, you’ll want to seek treatment before the disease progresses too far. It may be a good time to call Metro Vein Centers and schedule an appointment with the best in the business!