Chronic Venous Disease: Varicose Veins And Venous Insufficiency
Causes And Risk Factors
In chronic venous disease, the valves in leg veins malfunction and blood flows in the reverse direction (ie, venous reflux), pooling in the veins and creating increased venous pressure. The buildup of blood pressure causes the characteristic changes in varicose veins—stretching, twisting, and bulging of the superficial veins (Fort 2017a; Eberhardt 2014; Wittens 2015; Jones 2008).
Although dysfunction of the valves in leg veins is the typical cause of increased venous blood pressure, other factors can also contribute, including obstruction of the veins (eg, by blood clots) and decreased contraction of calf muscles (eg, due to leg immobility). When increased venous blood pressure in the legs occurs as a result of a deep vein thrombosis, it is termed post-thrombotic syndrome (Wittens 2015; Eberhardt 2014; Fort 2017b).
Inflammation may play a role in the progression of venous disease and contribute to complications such as blood clots and leg ulcers. Inflammation results in part from damage to vein walls caused by turbulent blood flow as well as elevated pressure within the veins (Poredos 2015; Ligi 2016; Bergan 2006). Studies have reported significantly increased levels of inflammatory markers such as C-reactive protein (CRP) and interleukin-6 (IL-6) in varicose vein blood compared with systemic blood (Lattimer 2016; Poredos 2015; Kalodiki 2015).
Risk factors for chronic venous disease and varicose veins include (Fort 2017a; Eberhardt 2014; NIH 2016; Scherger 2012):
- Increasing age
- Female gender
- Tall stature
- Family history of chronic venous disease
- Previous history of deep vein thrombosis in the legs
- Pregnancy; history of one or more previous pregnancies
- Prolonged sitting or standing