Figure 2.

A general view on the different etiological mechanisms of CVD. Primary CVD (left) is caused by different genetic and environmental factors and it is characterized by a persistent venous hypertension responsible for the onset and progression of the disease. Secondary CVD (middle) is preceded by a pathological event, which could be intravenous (DVT) or extravenous (e.g., calf muscle dysfunction, extrinsic tumoral mass or arterial compression). Congenital CVD (right) represent a small percentage of the problem, and it is caused by single gene mutations or chromosomic aberrations.