Venous reflux is a medical condition where blood flows backward in the veins of the legs, failing to return efficiently toward the heart. This backward flow prevents proper circulation and results in blood pooling in the lower limbs. When persistent over a long duration, this issue is termed Chronic Venous Insufficiency (CVI). This condition is highly prevalent, affecting approximately 40% of people in the United States.
How Veins Work and Where Reflux Starts
Veins in the legs must work against the force of gravity to transport deoxygenated blood upward toward the heart. This task is accomplished through the surrounding calf muscles, which contract and squeeze the veins, and a series of one-way valves inside the veins. These valves function like tiny pocket doors, opening to allow blood to pass through and immediately closing to prevent backflow.
Venous reflux begins when these valves become damaged, weakened, or fail to close completely. When the valve cusps cannot meet properly, blood that has been pumped upward falls back down, pooling in the lower section of the vein. This backward movement increases pressure within the vein, causing it to stretch and widen, which further prevents the valves from sealing. The resulting high pressure, known as venous hypertension, is the underlying cause of the symptoms and complications associated with CVI.
Recognizing the Signs of Venous Reflux
The initial signs of venous reflux often manifest as heaviness or fatigue in the legs, especially after long periods of standing or sitting. Patients report a dull, persistent aching or cramping sensation that is typically relieved by elevating the legs. Symptoms also include an uncomfortable restlessness in the legs, which often worsens in the evening hours.
As the condition progresses, sustained internal pressure causes fluid to leak out of the veins into surrounding tissues, leading to edema or swelling, particularly around the ankles and lower calves. Chronic high pressure causes inflammatory changes and the breakdown of red blood cells beneath the skin. This process leaves behind an iron-containing pigment, resulting in reddish-brown discoloration known as hyperpigmentation.
The skin in the affected area may become thickened and hardened, a change called lipodermatosclerosis. In advanced stages, ongoing inflammation and poor circulation can lead to the formation of venous stasis ulcers. These open sores often occur near the ankles and can be difficult to heal due to underlying circulatory impairment.
Who Is at Risk for Venous Reflux
A strong family history is a significant predisposing factor for developing venous reflux, suggesting a genetic component influencing vein wall or valve strength. Advanced age also contributes, as natural wear and tear on vein structures weakens the valves over time. Obesity places increased pressure on the abdominal and pelvic veins, impeding the return of blood flow from the legs and stressing the valve system.
Lifestyle factors also elevate the risk, such as occupations requiring prolonged periods of standing or sitting, which reduces the calf muscle pump action necessary for efficient circulation. A prior history of deep vein thrombosis (DVT)—a blood clot in the deep veins—is a major contributor because the clot can damage the valves, leading to post-thrombotic syndrome. Hormonal fluctuations, such as those during pregnancy, can also contribute to valve weakness and vein distension.
Treatment and Management Strategies
Diagnosis of venous reflux involves a duplex ultrasound, a non-invasive imaging test used to visualize the veins and measure the speed and direction of blood flow to confirm the presence and severity of backward flow. Initial management focuses on conservative strategies designed to improve blood return and reduce venous pressure. This includes regular exercise, which strengthens the calf muscles to enhance the pumping action.
Elevation of the legs above heart level several times a day is an effective way to drain pooled blood and reduce swelling. The most recommended conservative treatment is the use of compression stockings, which apply graduated pressure to the leg. This external pressure assists the veins in pushing blood back toward the heart and prevents fluid from leaking into the tissues.
For advanced cases where conservative measures are insufficient, minimally invasive procedures eliminate the problematic veins. Sclerotherapy involves injecting a chemical solution into smaller veins, causing them to scar and close so blood redirects to healthier vessels. For larger veins, thermal ablation techniques—using either laser energy or radiofrequency—heat the vein wall to cause it to collapse and seal shut. Once the damaged vein is closed, the body reroutes the blood through remaining healthy veins, effectively reducing backward flow and overall venous hypertension.