The patient’s history of smoking, claudication, absent pulses, and non-healing foot ulcers strongly indicates Peripheral Arterial Disease (PAD). PAD results from atherosclerotic narrowing of peripheral arteries, leading to reduced blood flow and ischemia, particularly in the lower extremities. Claudication is a key symptom due to muscle ischemia on exertion, while absent pulses confirm arterial occlusion. Non-healing ulcers arise from inadequate perfusion impairing wound healing. This vascular insufficiency differentiates PAD from neuropathy or venous causes, which present differently. Smoking is a major risk factor for the development and progression of PAD.

Reference: Harrison’s Principles of Internal Medicine, J. Larry Jameson, 20th Edition.