Peripheral arterial disease (PAD) is a clinical disorder leading to stenosis or occlusion of the noncardiac vessels. Atherosclerosis is the most common cause in adults over the age of 40 years. Risk factors for developing PAD include age older than 70 years, family history, smoking, diabetes, hypertension, hyperlipidemia, and homocysteinemia.

Symptoms develop when the metabolic demand of tissues is greater than vessels are able to deliver. Most patients with PAD are asymptomatic. In those who develop symptoms, look for extremity pain with activity that is relieved with rest (claudication), limb ischemia with the development of ulcers or gangrenous lesions, or critical acute limb ischemia leading to pallor, pulselessness, paresthesia, and poikilothermia.

Atherosclerosis is a type of arteriosclerosis that can lead to narrowing of blood vessels. When atherosclerotic plaques involve 70%-80% of the luminal diameter, blood flow may become limited, particularly during times of physical exertion and increased demand. Plaque rupture may cause occlusion of coronary vessels or cerebrovascular vessels, leading to ischemia and infarction that present as myocardial infarctions and strokes, respectively.