What’s the Difference Between Peripheral Artery Disease (PAD) and Chronic Venous Insufficiency?

Medically Reviewed by James Beckerman, MD, FACC on February 11, 2024
Written by Nicole Wu
4 min read

Peripheral artery disease (PAD) and chronic venous insufficiency (CVI) both affect your blood vessels and prevent your body from getting the oxygen-rich blood that it needs. The difference between the two lies in the type of blood vessel that isn’t working correctly. PAD affects your arteries, but CVI affects your veins. 

PAD and CVI are both vascular diseases that prevent healthy blood flow. It can be easy to mix them up because they share some common aspects, but they also differ in many ways. 

Both PAD and CVI have symptoms that cause problems in your legs. People with either disease might have leg, ankle, or foot aches along with pain, cramps, or skin discoloration. They might also have skin sores, or ulcers, that don't heal well. 

If you have PAD, you might not have any symptoms at all, or you might have leg numbness, tingling, and legs or feet that are different temperatures. People with CVI might have swelling legs, itchy skin, and more visible varicose veins.

Shared risk factors for both PAD and CVI include family history, age, obesity, smoking, and high blood pressure. If you have diabetes or high cholesterol, you are at a greater risk for PAD. Women and people who don't get enough exercise are more at risk for CVI‌.

Your arteries are responsible for transporting oxygen-rich blood away from your heart and to other parts of your body. Healthy artery walls are smooth and allow your blood to flow steadily without obstruction. PAD happens when your arteries become hardened, narrowed, or blocked and can no longer let blood flow freely. ‌

The most common cause of PAD is atherosclerosis, a condition where plaque builds up your arteries. The plaque is mostly made of fat, cholesterol, and calcium that sticks to your artery walls. Limb injury, artery inflammation, and exposure to high levels of radiation are other more rare peripheral artery disease causes.

People with family histories of heart attack, stroke, or other blood vessel disorders have a higher risk of PAD. As people age, the risk increases. People who smoke, are obese, or have high blood pressure or cholesterol levels are also at a greater risk than others. 

PAD affects over eight million Americans over the age of 40. It most commonly blocks blood flow to your legs and feet, but some types can affect blood flow to your brain, kidneys, or intestines.

PAD symptoms can be different for each person depending on the location and severity of the blocked arteries. Some people may have very mild symptoms or none at all. Some commonly reported peripheral artery disease symptoms include:

  • Leg pain, aches, or cramps while walking that stop when resting
  • Leg weakness, numbness, or tingling
  • Blue, pale, or discolored skin
  • Having one leg or foot feel colder than the other
  • Slow-healing foot or leg sores
  • Slow-growing leg hair and toenails

If left untreated, PAD can cause your legs to become painful even while resting, and you might be unable to get around well. Leg sores from PAD can cause infections and gangrene, or tissue death, from lack of blood flow. Infections can spread to other areas of your body like your muscles, bones, and bloodstream. 

The veins in your body must often fight gravity to keep moving blood up toward your heart. Muscles in your legs help the process by squeezing the veins when you walk or make other movements. As the blood flows up, one-way valves inside your veins prevent it from flowing backward and pooling in your legs. 

Sometimes your veins and the valves inside become damaged or don’t work as they should. Chronic venous insufficiency (CVI) happens when your veins can't effectively send oxygen-depleted blood back up into your heart from other parts of your body‌. 

CVI happens when your vein valves or walls are damaged. Damaged valves can't properly prevent blood from flowing backward. Damaged vein walls can twist, stretch, and swell, making it even harder for blood to return to your heart. Vein valve and wall damage can be caused by:

  • High blood pressure 
  • Sitting or standing for a long time
  • Blood clots in deep leg veins (deep vein thrombosis)
  • Leg injuries
  • Hormone changes
  • Hormonal birth control

‌Women, people over 50, people who are obese, and people who smoke are more at risk for vein damage. People who don't get enough exercise or have had multiple pregnancies are also at greater risk.

Chronic venous insufficiency symptoms affect your legs, feet, and ankles. Some common troubles include:

  • Aching or throbbing legs
  • Leg and ankle swelling 
  • Varicose veins
  • Rough, leathery leg skin
  • Itching feet or legs

Untreated CVI can also cause tiny blood vessels called capillaries to burst from the swelling and pressure in your legs. Burst capillaries can lead to painful ulcers, which are open sores that may not heal normally and can spread infection.