Peripheral vascular disease (PVD), also known as peripheral artery disease (PAD) or peripheral artery occlusive disease (PAOD), includes all diseases caused by the obstruction of large arteries in the arms and legs. PVD can result from atherosclerosis, inflammatory processes leading to stenosis, an embolism or thrombus formation. It causes either acute or chronic ischemia (lack of blood supply), typically of the legs.

Amputation is the most likely outcome in patients with critical limb ischaemia (ulceration, gangrene, rest pain), who do not have bypass surgery to improve the blood supply to the leg. In patients with critical limb ischaemia, ulceration and gangrene will not resolve without some form of intervention. Improving the blood supply to the leg can allow healing to take place, but the gangrenous areas still need removal to enable healing to take place. Arterial bypass surgery is indicated in patients with a threatened leg likely to require amputation, if left untreated (critical limb ischaemia). It can also be considered in patients with very severe disabling claudication. Arterial bypass surgery can save the leg or reverse severe disability.