ABSTRACT
Arterial disease is most commonly caused by atherosclerosis but there are several uncommon or rare non-atherosclerotic arterial diseases. Aneurysmal arterial disease may have a pathogenesis different from atherosclerosis. The causes of chronic venous disease are not fully understood but there is disturbance of normal venous flow due to valvular incompetence or venous obstruction. Thrombosis can complicate any arterial or venous disease. This chapter describes diseases that may be manifest at various sites, and conditions specific to a particular site are discussed in regional chapters.
