Understanding Peripheral Arterial Disease
Peripheral arteries deliver oxygen-rich blood to the tissues outside the heart. As you age, your arteries become stiffer and thicker. In addition, risk factors such as smoking and high cholesterol can damage the artery lining. This allows a buildup of fat and other materials (plaque) to form within the artery walls. The buildup of plaque narrows the space inside the artery and sometimes blocks blood flow. Peripheral arterial disease (PAD) occurs when blood flow through the arteries is reduced because of plaque buildup. It often happens in the legs and feet, but can also occur elsewhere in the body. If this buildup occurs in the a large artery in the neck (carotid artery), it can be a major contributor to stroke.
A healthy artery
An artery is a muscular tube. It has a smooth lining and flexible walls that allow blood to pass freely. When active, muscles need more oxygen, requiring increased blood flow. Healthy arteries can adapt to meet this need.
A damaged artery
PAD begins when the lining of an artery is damaged. This is often because of a risk factor, such as smoking or diabetes. Plaque then starts to form within the artery wall. At this stage, blood flows normally, so you’re not likely to have symptoms.
A narrowed artery
If plaque continues to build up, the space inside the artery narrows. The artery walls become less able to expand. The artery still provides enough blood and oxygen to your muscles during rest. But when you’re active, the increased demand for blood can’t be met. As a result, your leg may cramp or ache when you walk.
A blocked artery
An artery can become blocked by plaque or by a blood clot lodged in a narrowed section. When this happens, oxygen can’t reach the muscle below the blockage. Then you may feel pain when lying down (rest pain). This type of pain is especially common at night when you’re lying flat. In time, the affected tissue can die. This can lead to the loss of a toe or foot.