Chronic venous insufficiency (CVI) happens when the valves in your leg veins don't work well enough to push blood efficiently back up to your heart, so blood pools in your lower legs instead. It's extremely common, rarely dangerous on its own, and easy to confuse with other causes of leg swelling — including heart failure — which is exactly why it's worth understanding the difference.
What's Happening in Your Legs
Your leg veins contain one-way valves that keep blood moving upward against gravity as your calf muscles contract. When those valves weaken or become damaged, blood leaks backward and pools, raising pressure in the veins below — a process called venous reflux. Over time, that sustained pressure stretches the veins further (worsening the valve problem), and pushes fluid out into the surrounding tissue, causing the swelling that's usually the first noticeable symptom.
Common Symptoms
- Swelling in the ankles and lower legs, typically worse by the end of the day and better after a night lying flat
- Aching, heaviness, or fatigue in the legs, especially after standing or sitting for long periods
- Visible varicose veins (bulging, twisted veins) or smaller spider veins
- Itching or skin irritation over the lower legs
- Skin discoloration — a brownish or reddish tint near the ankles, from years of pressure and old blood breakdown products
- In advanced cases, thickened, hardened skin (lipodermatosclerosis) or slow-healing sores near the ankle (venous stasis ulcers)
Risk Factors
- Older age
- Family history of varicose veins or CVI
- Prolonged standing or sitting, particularly for work
- Pregnancy (multiple pregnancies raise risk further)
- Obesity
- A prior blood clot (deep vein thrombosis) in the leg, which can damage valves permanently
- Being female (women are affected somewhat more often, related partly to hormonal effects on vein walls)
How It's Different From Heart Failure Swelling
This distinction matters, since both cause leg swelling and often coexist in the same patient, especially older adults. A few features that point toward CVI rather than heart failure: swelling that's present for years without other symptoms, visible varicose veins, skin changes concentrated near the ankles, and swelling that improves substantially overnight with leg elevation. Heart failure swelling more often comes with shortness of breath, weight gain, fatigue, and swelling that doesn't fully resolve with elevation alone. When the picture isn't clear, your care team may check a BNP blood test and an echocardiogram to evaluate your heart directly. (See Heart Failure and Lab Tests & Diagnostics.)
How It's Diagnosed
- A physical exam, looking at the pattern of swelling, visible veins, and skin changes
- Venous duplex ultrasound — the main diagnostic test, which uses sound waves to visualize blood flow in your leg veins and identify where valves are failing or where reflux is occurring
- Additional testing (like a BNP or echocardiogram) if there's any question about whether heart failure is also contributing
Main Treatment Options
- Compression stockings — graduated compression garments are the cornerstone of treatment for most people, helping the calf muscles push blood upward more effectively; getting properly fitted (rather than buying generic compression socks) makes a meaningful difference in comfort and effectiveness
- Leg elevation — raising your legs above heart level for periods during the day meaningfully reduces swelling
- Regular movement and calf muscle activity — walking activates the "calf muscle pump," the body's natural mechanism for moving blood back up the leg; prolonged sitting or standing without movement makes CVI worse
- Weight management, since excess weight increases pressure on leg veins
- Skin care, to prevent breakdown and infection in more advanced cases
- Procedures for more severe cases — endovenous ablation (using heat or a chemical to close off a malfunctioning vein), sclerotherapy (an injection that closes smaller veins), or, less commonly today, surgical vein stripping; these are generally considered when conservative measures aren't enough or symptoms are significant
Living With It
CVI is a chronic, manageable condition for most people rather than one that's ever fully "cured" — consistent use of compression, movement, and elevation controls symptoms well for the majority of people and prevents progression to more serious skin complications.
When to Call Your Doctor vs. Go to the ER
Call your doctor if: swelling is new, worsening, only in one leg, or if you notice a new sore that isn't healing. Go to the ER if: one leg becomes suddenly and significantly more swollen, red, warm, and painful than the other — this can indicate a blood clot (deep vein thrombosis) and needs urgent evaluation. (See Deep Vein Thrombosis.)
Common Questions
Is this the same as varicose veins?
Varicose veins are one visible sign of CVI, but you can have CVI with significant symptoms and minimal visible veins, or visible veins with few symptoms — they're related but not identical.
Do I need surgery?
Most people are managed well with compression stockings, elevation, and movement alone; procedures are generally reserved for more severe or persistent cases.
Can CVI cause a blood clot?
CVI itself doesn't directly cause DVT, but the two share risk factors and can occur together, which is part of why sudden one-sided swelling always deserves prompt evaluation.
Will compression stockings work if I don't wear them consistently?
Not as well — they work by consistent, graduated pressure throughout the day, so regular daily use (put on before swelling starts, typically first thing in the morning) makes the biggest difference.