The initial diagnosis of PAD begins with a thorough history and physical examination. Patients in whom a diagnosis of PAD should be considered include those with the following risk factors: 
- Age ≥ 65
- Age 50-64 with risk factors including diabetes, tobacco use (current or former), hypertension, dyslipidemia, or family history of PAD
- Age < 50 with diabetes and 1 additional atherosclerosis risk factor
- Atherosclerotic disease in other vascular beds including coronary, carotid, renal, or mesenteric
Patients at high risk for PAD should be screened for exertional leg symptoms. Of importance, only a minority of patients with PAD will report classic intermittent claudication or present with ischemic rest pain. Since a significant number of PAD patients have co-morbidities such as spinal stenosis, peripheral neuropathy, and osteoarthritis, their symptoms will be more consistent with atypical leg pain that may occur at rest or with exertion . In patients who report no leg symptoms, studies have shown that some degree of functional impairment is usually present . Therefore, even in high-risk patients who are asymptomatic, a thorough history assessing functional capacity is important to detect underlying PAD.