What is the definition of peripheral vascular disease?

The definition of peripheral vascular disease (PVD) is characterized by a condition that primarily affects the blood vessels outside of the heart and brain. This encompasses a range of issues that can occur in arteries and veins located in the limbs, particularly the legs. PVD is most commonly linked with atherosclerosis, where fatty deposits build up in the artery walls, narrowing the vessels and impeding blood flow. This can lead to symptoms such as pain, cramps, and fatigue in the affected limbs, especially during physical activity.

In contrast, the other options focus on more specific areas or types of blood vessel issues. For instance, a disease affecting blood vessels only in the head refers to conditions such as cerebrovascular disease, which doesn't encompass the broader scope of PVD. A blockage in the veins of the heart describes a coronary artery blockage, which is a different cardiovascular issue. Similarly, a condition involving arteries in the pulmonary system pertains to pulmonary vascular disease, which also does not relate to the peripheral vessels that PVD addresses. The key aspect of PVD is its effect on blood vessels outside of the heart, solidifying choice B as the accurate definition.