What is chronic venous insufficiency (CVI)?
Chronic venous insufficiency (CVI) is a condition that occurs when the venous wall and/or valves in the leg veins are not working effectively, making it difficult for blood to return to the heart from the legs. CVI causes blood to “pool” or collect in these veins, and this pooling is called stasis.
Valve Inside Vein
What causes chronic venous insufficiency?
Veins return blood to the heart from all the body’s organs. To reach the heart, the blood needs to flow upward from the veins in the legs. Calf muscles and the muscles in the feet need to contract with each step to squeeze the veins and push the blood upward. To keep the blood flowing up, and not back down, the veins contain one-way valves.
Chronic venous insufficiency occurs when these valves become damaged, allowing the blood to leak backward. Valve damage may occur as the result of aging, extended sitting or standing or a combination of aging and reduced mobility. When the veins and valves are weakened to the point where it is difficult for the blood to flow up to the heart, blood pressure in the veins stays elevated for long periods of time, leading to CVI.
CVI most commonly occurs as the result of a blood clot in the deep veins of the legs, a disease known as deep vein thrombosis (DVT). CVI also results from pelvic tumors and vascular malformations, and sometimes occurs for unknown reasons. Failure of the valves in leg veins to hold blood against gravity leads to sluggish movement of blood out of the veins, resulting in swollen legs.
Chronic venous insufficiency that develops as a result of DVT is also known as post-thrombotic syndrome. As many as 30 percent of people with DVT will develop this problem within 10 years after diagnosis.
What are the risk factors for chronic venous insufficiency?
If you have risk factors for CVI, you are more likely than other people to develop the disease. The most important risk factors are:
- Deep vein thrombosis (DVT)
- Varicose veins or a family history of varicose veins
- Extended periods of standing or sitting
- Female sex
- Age over 50
Who is affected by chronic venous insufficiency?
An estimated 40 percent of people in the United States have CVI. It occurs more frequently in people over age 50, and more often in women than in men.