Peripheral Arterial Disease

Causes

• Atherosclerosis (Primary Cause):
  • The most common cause of PAD. It involves the gradual buildup of plaque (made of fat, cholesterol, calcium, and other substances) inside the artery walls.
  • This plaque hardens and narrows the arteries, restricting blood flow to the limbs.
• Risk Factors for Atherosclerosis (and thus PAD):
  • Smoking: The most significant and powerful risk factor for PAD. Smoking damages blood vessels, accelerates atherosclerosis, and worsens symptoms.
  • Diabetes Mellitus: High blood sugar levels damage blood vessels, particularly the small arteries, and accelerate atherosclerosis throughout the body.
  • High Blood Pressure (Hypertension): Damages artery walls, making them more prone to plaque formation.
  • High Cholesterol (Hyperlipidemia): High levels of LDL ("bad") cholesterol contribute to plaque buildup.
  • Age: PAD becomes more common with increasing age, particularly after 50.
  • Family History: A family history of PAD, heart disease, or stroke increases an individual's risk.
  • Obesity: Contributes to other risk factors like diabetes and high blood pressure.
  • Lack of Physical Activity: Sedentary lifestyle is associated with higher risk.
  • Kidney Disease: Chronic kidney disease is a strong independent risk factor.
  • High Homocysteine Levels: An amino acid that, in high levels, can damage blood vessel linings.
• Less Common Causes:
  • Blood Vessel Inflammation (Vasculitis): Such as Takayasu's arteritis or Buerger's disease (thromboangiitis obliterans).
  • Injury to the Limbs.
  • Unusual Ligament or Muscle Abnormalities: That compress arteries.
  • Radiation Exposure.

Symptoms

• Claudication (Leg Pain with Exertion):
  • The classic symptom of PAD. It is muscle pain or cramping in the legs (most commonly calf, but also thigh or buttocks) that is triggered by activity (e.g., walking, climbing stairs) and disappears after a few minutes of rest.
  • The location of the pain depends on where the artery is narrowed.
• Leg Numbness or Weakness.
• Coldness in the Lower Leg or Foot: Especially compared with the other side.
• Sores or Ulcers on the Toes, Feet, or Legs: That don't heal or heal very slowly (indicating critical limb ischemia).
• Change in the Color of the Legs: Paleness when elevated, reddish-blue when dangling.
• Hair Loss or Slower Hair Growth: On the legs and feet.
• Slower Growth of Toenails.
• Shiny Skin on the Legs.
• No Pulse or a Weak Pulse: In the legs or feet.
• Erectile Dysfunction in Men: If PAD affects the arteries supplying the pelvis (aortoiliac disease).
• Pain at Rest: (Critical Limb Ischemia) Persistent pain in the feet or toes, even when resting, especially at night, often worse when lying flat. This indicates severe PAD.
• Gangrene: (Severe, late-stage) Tissue death due to lack of blood flow, leading to infection and potentially limb amputation.

Diagnosis

• Medical History and Physical Exam: The doctor will inquire about symptoms (especially claudication), risk factors, and family history. The exam involves checking pulses in the legs and feet, looking for skin changes, and listening for bruits (abnormal sounds) over arteries.
• Ankle-Brachial Index (ABI):
  • The most common and definitive non-invasive test for PAD.
  • It compares blood pressure measured at your ankle to blood pressure measured at your arm. A low ABI (less than 0.90) indicates narrowed arteries.
  • May be done before and after exercise to unmask milder PAD.
• Doppler Ultrasound (Duplex Ultrasound):
  • Uses sound waves to create images of blood vessels and measure blood flow.
  • Can identify the location and severity of arterial narrowing or blockages.
• Treadmill Walking Test: Measures the walking distance before claudication pain occurs and assess changes in ABI after exercise.
• CT Angiography (CTA):
  • Uses CT scans with contrast dye to produce detailed images of blood vessels, clearly showing blockages.
  • Useful for pre-operative planning.
• MR Angiography (MRA):
  • Similar to CTA, but uses MRI technology and contrast dye to visualize arteries, without radiation exposure.
• Conventional Angiography (Catheter Angiography):
  • An invasive procedure considered the "gold standard" for detailed visualization of arteries. A catheter is inserted into an artery, and contrast dye is injected to highlight the vessels on X-ray.
  • Usually performed when an intervention (angioplasty or surgery) is being considered.

Treatment

• Lifestyle Modifications (Cornerstone of Therapy):
  • Smoking Cessation: Absolutely critical. Quitting smoking is the most effective way to slow disease progression and improve symptoms.
  • Regular Exercise: Especially supervised exercise programs, are highly effective for improving walking distance and reducing claudication pain. Walking regularly is key.
  • Healthy Diet: Low in saturated/trans fats, cholesterol, refined sugars; rich in fruits, vegetables, whole grains.
  • Weight Management: Achieve and maintain a healthy weight.
• Medications:
  • Statins: (e.g., atorvastatin, rosuvastatin) To lower cholesterol, stabilize plaque, and reduce cardiovascular events.
  • Antiplatelet Medications: (e.g., aspirin, clopidogrel - Plavix) To prevent blood clots from forming and reduce the risk of heart attack and stroke.
  • Blood Pressure Medications: To control hypertension.
  • Diabetes Medications: To control blood sugar levels.
  • Cilostazol (Pletal): A specific medication approved to treat claudication symptoms, improving walking distance.
  • Pentoxifylline: Less commonly used for claudication.
• Procedures (for severe symptoms or non-healing wounds):
  • Angioplasty and Stenting: A catheter with a balloon is inserted into the narrowed artery and inflated to widen it. A stent (mesh tube) may be placed to keep the artery open.
  • Atherectomy: A procedure to remove plaque from the artery using a specialized device.
• Surgical Procedures (for extensive blockages or critical limb ischemia):
  • Bypass Grafting: A synthetic tube or a vein from another part of the body is used to create a bypass around the blocked segment of the artery, rerouting blood flow.
  • Endarterectomy: Surgical removal of plaque from the inside of the artery.
• Foot Care: Meticulous foot care is essential, especially for individuals with diabetes, to prevent infections, non-healing wounds, and ultimately amputation.

Living With Peripheral Arterial Disease

Peripheral arterial disease is treated in two directions at once: the legs, where walking is the most effective therapy available, and the rest of the arteries, where the same disease is quietly threatening the heart and brain.

Walking is the treatment, and it has a technique

Walk until the leg pain is moderate, stop and rest until it passes, and repeat, for thirty to forty-five minutes three or more times a week for at least twelve weeks. Done that way, walking distance typically improves more than any medication or stent, because the legs grow collateral circulation in response to the pain. Supervised programs are covered by Medicare; at home, early morning or an air-conditioned mall avoids the heat, and our 30-day walking challenge and peripheral artery disease leg pain articles give a structure.

The medications that protect the heart and brain

A high-intensity statin such as atorvastatin or rosuvastatin is prescribed regardless of the cholesterol number, because PAD carries the same risk of heart attack and stroke as established coronary artery disease. Aspirin or clopidogrel is standard, and adding low-dose rivaroxaban to aspirin further reduces limb and heart events in people at higher risk. Blood pressure and diabetes are controlled to target, and beta-blockers, once thought to worsen claudication, are safe. Quitting smoking matters more than any of it; varenicline and our smoking cessation guide are where to start.

Feet: the part that is lost

Amputation in PAD usually begins with a small wound that could not heal, so the feet are inspected daily, kept moisturized but dry between the toes, and never bare, even on the beach or pool deck, where hot sand and concrete burn skin that cannot repair itself. Shoes are properly fitted, nails are cut straight across or by a podiatrist, and heating pads are avoided. Any sore that has not healed in two weeks is seen promptly. Diabetic neuropathy removes the pain that would otherwise warn you, and our diabetic foot care guide applies to everyone with PAD.

What it is confused with, and what travels with it

Leg pain that eases by sitting or bending forward rather than by simply standing still is usually spinal stenosis, and an ankle-brachial index settles the question when both are possible. Because atherosclerosis is systemic, PAD prompts a one-time abdominal aortic aneurysm ultrasound and attention to carotid artery disease symptoms. Erectile dysfunction in a man with PAD is the same disease in a different artery.

The emergency

A leg that suddenly becomes cold, pale, numb, weak, and painful is acute limb ischemia, and the limb survives only if an artery is reopened within hours; call 911. Foot pain at rest that eases when the leg hangs down, and a wound turning black, are urgent. Our cardiovascular team coordinates care with vascular surgery. NHLBI and the Society for Vascular Surgery publish patient guidance.

If you have leg pain when walking that stops with rest, or a foot sore that has not healed in two weeks, schedule a visit.