Arteries carry oxygenated blood and nutrients from the heart to the rest of the body. The aorta, the largest artery in the body, arches upward from the top of the heart and then descends through the middle of the torso. Smaller arteries branch off from the aorta and distribute blood to muscles, organs and other body tissues.

At about the level of the belly button, the aorta splits into two branches. These branches, called the common iliac arteries, continue to branch off as they run through the pelvis and into the upper thighs. The main artery in each leg, the femoral artery, is an extension of each iliac artery. Each leg’s femoral artery begins at the groin and branches into numerous smaller arteries all the way down to the toes. These smaller arteries bring fresh blood to the thighs, knees, lower legs, and feet.

Leg artery disease is a partial or complete blockage of circulation through the arteries of the leg. This compromised blood flow can cause problems in the hip, buttock, thigh, knee, shin or upper foot.

THE IMPACT OF ATHEROSCLEROSIS

As people age, the normal flow of blood through the legs and feet can be affected by the buildup of plaque inside the arteries. The plaque is made up of cholesterol or lipids, calcium and fibrous scar tissue. Doctors believe that this buildup of atherosclerotic plaque is more likely to occur at sites where arteries divide or give off smaller branches, because these areas are subject to greater turbulence in the flow of the blood.

Over time, these plaques continue to grow on arterial walls as cholesterol circulates in the blood, and as the plaques enlarge the arteries become narrow and stiffened. This process is called atherosclerosis, commonly known as ‘hardening of the arteries’ because the plaque buildup thickens the walls of the arteries, narrowing the space through which blood flows. When this narrowing occurs in leg arteries, the circulation of blood through the leg is compromised. Poor circulation in turn can cause ischemia, or a decrease in blood flow that causes insufficient oxygen levels.

Atherosclerosis may also cause coronary heart disease, or CHD, when plaque causes blockages in the arteries that bring blood to the heart muscle. Carotid artery disease, or plaque build up that interferes with the flow of blood to the brain, is also caused by atherosclerosis. These conditions are serious because CHD can cause heart attacks, and carotid artery disease can result in stroke.

Doctors estimate that 30 to 40 percent of people with CHD or carotid artery disease also suffer from leg artery disease or another form of PAD, and 50 to 60 percent of patients with PAD will develop either CHD or carotid artery disease.