What Causes Varicose Veins
Varicose veins result from venous valvular reflux caused by a combination of genetic predisposition, incompetent valves, weakened vascular walls, and increased intravenous pressure. 1, 2
Primary Pathophysiologic Mechanism
The underlying cause involves a loss of elasticity in the vein wall, leading to failure of the valve leaflets to fit together properly. 1 Rather than blood flowing normally from distal to proximal and superficial to deep, the incompetent valves allow blood to flow in reverse. 1 This reversed flow creates increased pressure on the affected venous system, causing larger veins to become elongated and tortuous. 1
Shear stress on venous endothelial cells from reversed or turbulent blood flow and inflammation are also critical etiologic factors. 1
Contributing Mechanisms
Decreased vein wall elasticity allows pooling of blood within the veins and their subsequent enlargement. 3
Chronic venous hypertension plays an important role in disease development and progression. 4
Constant venous wall inflammation contributes to the pathological process. 4
Hereditary variation influences susceptibility to developing varicose veins. 4
Established Risk Factors
The American Academy of Family Physicians identifies several key risk factors: 1
Family history of venous disease is a significant predictor. 1, 2
Female sex increases risk, particularly with multiple pregnancies. 1, 2, 3
Older age correlates with increased prevalence. 2
Chronically increased intra-abdominal pressure from obesity or pregnancy. 2
Prolonged standing worsens symptoms and contributes to disease progression. 2, 5
Clinical Implications
The exact pathophysiology remains debated, but the consensus centers on valvular incompetence as the primary defect. 1 In most cases, the valvular dysfunction is presumed to be caused by primary vein wall weakness rather than valve leaflet abnormalities alone. 1 This distinction matters because treatment must address the underlying venous reflux at junctional points (saphenofemoral or saphenopopliteal junctions) to prevent recurrence. 6
The disease is progressive, typically deteriorating over time to cause discomfort, swollen ankles, skin damage, leg ulcers, superficial venous thrombosis, and venous bleeding if left untreated. 7