Peripheral Vascular Disease (PVD) and Peripheral Artery Disease (PAD) are frequently confused terms describing conditions involving blood vessels outside of the heart and brain. While often used interchangeably, understanding the specific relationship between PVD and PAD is important for grasping the cause, symptoms, and appropriate treatment.
Clarifying the Terminology: PVD and PAD
Peripheral Vascular Disease (PVD) is an overarching term encompassing any condition that affects the peripheral blood vessels, including arteries, veins, and lymphatic vessels. PVD describes disorders that impair blood circulation, most commonly in the legs and feet. Since PVD covers all three vessel types, it can be caused by various issues, such as blood clots, inflammation, or damage to vein valves.
Peripheral Artery Disease (PAD) is a specific type of PVD that focuses exclusively on the arteries. PAD is characterized by the narrowing or blockage of arteries, typically in the lower extremities, due to a buildup of fatty deposits called plaque. While all cases of PAD fall under the umbrella of PVD, not all PVD is considered PAD. The key difference is the specific vessel affected: PAD involves the arteries, which carry oxygenated blood away from the heart.
Understanding PAD: Causes and Risk Factors
The primary cause of PAD is atherosclerosis, a progressive disease where plaque, composed of cholesterol, fat, and cellular waste, accumulates along the inner walls of the arteries. This accumulation causes the arteries to harden and narrow, restricting the flow of oxygen-rich blood to the muscles and tissues in the limbs.
Several factors increase the risk for PAD. The most significant modifiable risk factor is smoking, which damages the lining of blood vessels and increases plaque buildup. Other chronic conditions that harm arterial walls include diabetes, where high blood sugar damages vessels over time. High blood pressure (hypertension) and high cholesterol levels also contribute to plaque formation. A family history of vascular disease and advancing age are non-modifiable risk factors.
Recognizing the Signs: Common Symptoms of PAD
The most characteristic symptom of PAD is intermittent claudication, which is pain, aching, cramping, or fatigue in the leg muscles during physical activity. This discomfort occurs because narrowed arteries cannot supply enough oxygenated blood to meet the increased metabolic demands of the working muscles. The pain consistently resolves after a few minutes of rest.
While claudication is the telling sign, many people with PAD experience no symptoms or display other, less specific indicators. Common signs include numbness or weakness in the legs and feet. The skin on the lower legs may appear shiny or pale, and one foot may feel distinctly colder than the other due to compromised circulation. In more severe cases, poor blood flow can lead to slow-healing sores or ulcers on the feet and toes.
Diagnosis and Treatment Options
Diagnosing PAD typically begins with a non-invasive screening tool called the Ankle-Brachial Index (ABI). This simple test compares the blood pressure measured at the ankle to the blood pressure measured at the arm, with a ratio below 0.90 indicating a likely obstruction in the leg arteries. If the ABI is abnormal or inconclusive, a doctor may order further tests, such as a Doppler ultrasound to visualize blood flow or an angiography to map the exact location and severity of arterial blockages.
Treatment for PAD is built on three main pillars: lifestyle changes, medication management, and, if necessary, revascularization procedures. Lifestyle modifications are foundational, with smoking cessation being the most impactful step to halt disease progression. Regular, supervised exercise programs are also prescribed to help the body grow new collateral blood vessels and improve walking distance.
Medications are used to manage the underlying risk factors and prevent cardiovascular events like heart attack or stroke. This often includes antiplatelet agents, such as aspirin or clopidogrel, to reduce the risk of blood clots, and statins to lower cholesterol levels. For patients whose symptoms significantly limit their daily life, surgical options may be considered, which include angioplasty and stenting to open the blocked artery, or bypass surgery to reroute blood flow around the obstruction using a graft.