CVI – Chronic Venous Insufficiency

Chronic Venous Insufficiency (CVI) is a progressive medical condition in which the valves that carry blood from the legs toward the heart no longer function, causing blood to pool in the legs and the veins to swell. Varicose veins, which are often misunderstood as a purely cosmetic issue, can progress to this more serious condition if left untreated.

Underlying Cause of CVI

Healthy leg veins are designed to allow blood to flow against gravity from the legs back up toward the heart. Inside the veins are tiny valves that open and close to help control the flow and pressure.1 CVI occurs when stresses on the venous system like pregnancy, age or standing for long periods of time weaken and stretch vein structure. When the veins become weakened or diseased, the blood flow is obstructed and blood pools in the legs. This impaired blood flow (or reflux) causes veins to expand, lose form and protrude from beneath the skin.


Of the over 30 million Americans affected by varicose veins or CVI, only 1.9 million seek treatment annually, while the vast majority remain undiagnosed and untreated.*,2,3 Without treatment, those with the disease may experience progressive symptoms that can be debilitating and significantly impact quality of life. In fact, more people lose work time over vein disorders than from artery disease.4

Those who suffer from CVI may experience:

  • Leg heaviness and fatigue
  • Leg or ankle swelling
  • Leg pain, aching or cramping
  • Skin changes
  • Ulcers, open wounds or sores

Who is at risk?

Individuals with untreated varicose veins are at risk for developing CVI, as the symptoms can progress and become more serious over time. CVI can occur in anyone at any age; however, increased age is a risk factor. CVI tends to be more prevalent in women who have been pregnant, those who have a family history of the condition or those whose occupations require prolonged standing. Obesity is also a risk factor.5

Factors that can increase risk for CVI

  • Family history of varicose veins
  • Increasing age for both men and women
  • Pregnancy
  • Occupations requiring prolonged standing
  • Obesity


Diagnosing CVI is done through simple physiologic or imaging tests conducted in a physician’s office or vascular lab. The Dual Mode PADnet 2.0 supports CVI testing using air plethysmography or APG.

Below is a table comparing APG to other Duplex imaging and photo plethysmography published in the Circulation article entitled, “Chronic Venous Insufficiency.”

Chronic Venous Insufficiency