Vascular disease is any condition that affects your blood vessels, the network of arteries, veins, and capillaries that moves blood throughout your body. It ranges from narrowed arteries that starve your legs of oxygen to blood clots that can travel to your lungs, and it collectively affects hundreds of millions of people worldwide. Peripheral artery disease alone impacts more than 200 million people globally and over 12 million Americans.
How the Vascular System Works
Your vascular system has three main components. Arteries carry oxygen-rich blood away from your heart to your organs and tissues. Veins carry blood and waste products back to your heart. Capillaries, the smallest vessels, connect the two and have thin, permeable walls that allow nutrients and waste to pass between your blood and surrounding tissue.
Vascular disease can strike any part of this network. Arterial diseases involve blockages or weakened walls in arteries. Venous diseases involve faulty valves or clots in veins. Lymphatic conditions affect the separate drainage system that manages fluid balance. Each type produces distinct symptoms and carries different risks.
Atherosclerosis: The Root of Most Arterial Disease
The most common driver of arterial vascular disease is atherosclerosis, a gradual buildup of fatty deposits inside artery walls. It starts when the inner lining of an artery becomes damaged, often by high blood pressure, smoking, or high cholesterol. Once that lining is compromised, cholesterol particles slip beneath it and become trapped, where they undergo chemical changes that trigger inflammation.
White blood cells rush to the area and begin absorbing the trapped cholesterol, swelling into what researchers call foam cells. These foam cells cluster together with fatty debris to form a streak along the artery wall. Over time, smooth muscle cells migrate into the area and build a tough, fibrous cap over the growing deposit. Beneath that cap sits a soft core of dead cells and lipids. The result is a plaque that narrows the artery and restricts blood flow. If the fibrous cap ruptures, a blood clot can form on the spot and block the artery entirely, which is the mechanism behind most heart attacks and many strokes.
Peripheral Artery Disease
Peripheral artery disease (PAD) is atherosclerosis that develops in the arteries supplying your legs and feet. The hallmark symptom is claudication: cramping or aching in your calf muscles when you walk that relieves itself within minutes of resting. It happens because your leg muscles need more oxygen during activity than narrowed arteries can deliver.
Beyond cramping, PAD can cause coldness in one foot or lower leg, noticeable hair loss on the legs and feet, shiny or discolored skin, and slow-healing sores. About 3 to 4.5 percent of adults over 40 have PAD when tested, and the condition is roughly equal between men and women. In severe cases, blood flow drops so low that tissue begins to die, a stage called critical limb ischemia that affects about 1.3 percent of U.S. adults and can lead to amputation.
A simple office test called the ankle-brachial index (ABI) compares blood pressure at your ankle to blood pressure in your arm. A normal reading falls between 1.00 and 1.40. Values between 0.91 and 0.99 are borderline, 0.41 to 0.90 indicate mild to moderate PAD, and anything below 0.40 signals severe disease.
Carotid Artery Disease and Stroke Risk
The same plaque-building process can narrow the carotid arteries, the two large vessels on either side of your neck that supply blood to your brain. Significant narrowing here raises the risk of stroke, and that risk climbs in direct proportion to how blocked the artery becomes. With modern medical treatment, someone with moderate carotid narrowing faces less than a 5 percent chance of stroke over five years. For severe narrowing (70 percent blockage or more), that five-year risk rises to roughly 15 percent.
Carotid disease often produces no symptoms until a stroke or mini-stroke occurs, which is why doctors sometimes check for it in people with multiple cardiovascular risk factors.
Aneurysms
An aneurysm is a bulge in a weakened section of an artery wall. The most common and most dangerous location is the abdominal aorta, the large artery running through your midsection. Most abdominal aortic aneurysms (AAAs) grow silently for years and are discovered incidentally during imaging for something else. The danger is rupture: if the wall gives way, internal bleeding can be fatal within minutes.
Doctors traditionally recommend repair when an AAA reaches 5.5 centimeters in men or 5.0 centimeters in women, though newer research suggests those thresholds may be conservative for many patients. The optimal size for repair depends on age and overall health. For a 60-year-old man in average health, recent analysis puts the ideal threshold closer to 6.9 centimeters; for a 60-year-old woman, about 6.1 centimeters. Older or sicker patients can often safely wait longer because the risks of surgery begin to outweigh the risk of rupture.
The U.S. Preventive Services Task Force recommends a one-time ultrasound screening for men aged 65 to 75 who have ever smoked (defined as 100 or more cigarettes in a lifetime). Men in that age range who have never smoked may still benefit from selective screening. For women who have never smoked and have no family history, routine screening is not recommended because AAAs are far less common in this group.
Venous Disease
Venous disease behaves differently from arterial disease. Instead of blockages caused by plaque, the problem is usually faulty one-way valves inside the veins. These valves normally prevent blood from flowing backward under gravity. When they weaken, blood pools in the lower legs, raising pressure inside the veins.
Early signs include swelling, a feeling of heaviness or aching in the legs, and visible spider veins or varicose veins. As the condition progresses, skin around the ankles may darken, thicken, and become itchy. Restless legs are a common complaint. In advanced cases, open sores called venous ulcers develop on the lower legs. These ulcers can leak fluid, become infected, and take months to heal without proper compression and wound care.
Blood Clots: DVT and Pulmonary Embolism
Deep vein thrombosis (DVT) is a blood clot that forms inside a deep vein, usually in the leg. It often causes swelling, warmth, and pain in one calf or thigh, though some DVTs produce no symptoms at all. The serious risk is that part of the clot breaks loose, travels through the bloodstream, and lodges in an artery of the lung. This is a pulmonary embolism, which can be life-threatening because it blocks blood from picking up oxygen.
DVT and pulmonary embolism are collectively called venous thromboembolism. Risk factors include prolonged immobility (long flights, bed rest after surgery), certain blood-clotting disorders, pregnancy, and cancer. Swelling and pain in one leg that comes on suddenly, especially after a period of inactivity, warrants prompt medical evaluation.
Risk Factors That Cut Across All Types
Arterial and venous diseases share several risk factors, though they weight them differently. Smoking is the single strongest modifiable risk factor for both PAD and aortic aneurysms, because chemicals in tobacco directly damage vessel walls and accelerate plaque formation. High blood pressure forces arteries to work harder and weakens their structure over time. High cholesterol feeds the atherosclerosis process. Diabetes damages small and large vessels alike and impairs healing.
Age is the most powerful non-modifiable factor. Arterial disease becomes increasingly common after 50, and venous valve failure tends to worsen with each decade. A family history of vascular disease, heart attack, or stroke also raises your baseline risk.
How Vascular Disease Is Managed
Treatment depends on the type and severity, but most vascular disease management starts with the same foundation: controlling the underlying risk factors. Quitting smoking, managing blood pressure, and lowering cholesterol with statin therapy are the cornerstones. Guidelines call for high-intensity statin treatment in all patients with PAD, aiming to cut cholesterol levels by at least 50 percent.
Blood-thinning medications reduce the risk of clots forming on top of existing plaques. Low-dose aspirin or a related antiplatelet drug is standard for most people with arterial disease. In some cases, a combination of a low-dose blood thinner and aspirin provides additional protection, particularly after procedures to open blocked arteries.
For PAD specifically, one medication has been shown to improve walking distance by easing blood flow to the legs, with benefits appearing about four weeks after starting. Structured walking programs, where you walk until symptoms appear, rest, and repeat, are also a proven way to extend pain-free walking distance over time.
Procedures range from minimally invasive catheter-based techniques (threading a balloon or stent through a blood vessel to open a blockage) to open surgery for severe disease or large aneurysms. For venous disease, compression stockings and leg elevation are first-line treatments, with procedures available to close off or remove damaged veins when conservative measures aren’t enough.
Arterial vs. Venous Symptoms at a Glance
- Arterial disease: leg pain or cramping during activity that eases with rest, coldness in the foot, non-healing sores, pale or shiny skin, weak pulses in the feet.
- Venous disease: swelling and heaviness that worsen with standing, skin darkening around the ankles, visible varicose veins, restless legs, ulcers that tend to form near the inner ankle.
The distinction matters because the treatments are different. Compression helps venous disease but can be harmful if significant arterial blockage is also present. If you have leg symptoms, the type of vascular disease determines the right approach.