Can you explain the difference between pad (peripheral artery disease) and pvd (peripheral vascular disease)?

Actually None: The diseases involved and the problems caused are essentially the same. But over time it has become standard to refer to these problems as pad.

They are the same: We prefer to use the term pad now but when people use the older term, pvd, they mean the same thing.

Alternative name: Peripheral artery disease is a condition of the blood vessels that results in narrowing and hardening of the arteries that supply the lower extremities. Peripheral vascular disease is just an alternative name for the same condition.