The stenosing changes in PAD are largely arteriosclerotic. A small proportion of patients have inflammatory, dyskinetic and traumatic vascular diseases of PAD.
Many epidemio-logical studies have shown that where certain risk factors are present, arterial occlusive disease occurs more often than in patients without those features. Most cases of PAD involve chronic abfilterating arteriosclerosis obliterans (> 95%) which is attributable to the main risk factors heavy smoking (nicotine abuse) and diabetes mellitus. However, arterial hyper-tension, hypercholesterolemia and lack of exercise also contribute to the progression of this disease. If several risk factors occur together, this is particularly serious: the presence of three or more risk factors results in a six times greater likelihood of PAD, two factors increase the risk fourfold, and even one risk factor means 2.5 times the risk.
In about 5% of cases peripheral arterial occlusive disease has rare causes such as e.g. Thrombangiitis obliterans (Winiwarter-Buerger´s disease) or the Takayasu-Syndrome.

(Additional special forms include: cystic adventitial degeneration, popliteal compression syndrome, popliteal aneurysm, fibromuscular dysplasia, Raynaud´s disease, acrocyanosis, erythromeralgia, other vasculitides: e.g. temporal arteritis)