Chronic Venous Insufficiency (CVI)

Introduction

Chronic venous insufficiency, often shortened to CVI, is a long-term condition in which the veins in your legs have difficulty sending blood back up to your heart. Over time, this leads to swelling, aching, skin changes, varicose veins, and in more advanced cases, open sores called venous ulcers.

If you have been told you have CVI — or if you have varicose veins, leg swelling, or a slow-healing ankle wound that has been linked to your veins — this guide is written for you. It explains what is happening inside your legs, how doctors stage and diagnose the condition, the full range of treatments available today, and what living well with CVI looks like over months and years.

To understand CVI, it helps to picture how blood normally moves through your legs. Arteries carry blood downward from the heart. Veins carry it back up. Returning blood against gravity is a hard job, and your body uses two main tools to do it:

• Calf muscle pump: Every time you walk, your calf muscles squeeze the deep veins and push blood upward.
• One-way valves: Tiny flap-like valves inside your veins open to let blood move upward and close to stop it from flowing back down.

In chronic venous insufficiency, these valves stop working properly, or the veins themselves become stretched, weakened, or blocked. Blood then pools in the lower legs — a problem doctors call venous reflux or venous hypertension (sustained high pressure inside the leg veins). That pressure is the root cause of nearly every CVI symptom, from heaviness and swelling to skin damage and ulcers.

CVI is part of a broader spectrum called chronic venous disease. At one end are simple spider veins or small varicose veins that mostly cause cosmetic concern. At the other end are advanced skin changes and ulcers that need long-term wound care. The same underlying process — failing valves and high venous pressure — runs through all of it.

The CEAP Classification: How Doctors Stage CVI

• C0: No visible or palpable signs of venous disease.
• C1: Spider veins (telangiectasias) or small reticular veins.
• C2: Varicose veins — bulging, rope-like veins.
• C3: Swelling (oedema) of the leg.
• C4: Skin changes — brown discolouration (hyperpigmentation), eczema, or thickened skin (lipodermatosclerosis).
• C5: A venous ulcer that has healed.
• C6: An active, open venous ulcer.

This system matters because the right treatment depends a lot on where you sit on this scale. Someone with mild C2 varicose veins and aching legs has very different priorities from someone with a C6 ulcer that has not healed for months.

Causes and Risk Factors

CVI usually develops because of one or both of two underlying problems:

Primary venous disease

This is the most common form. The vein walls and valves become weak over time, often for reasons related to genetics, hormones, and the cumulative effects of gravity over many years of standing. The valves stop closing fully, blood leaks backward (reflux), and pressure builds up.

Post-thrombotic syndrome

This form develops after a deep vein thrombosis (DVT) — a blood clot in a deep leg vein. Even after the clot is treated, the inside of the vein and its valves can be permanently damaged, and the vein may remain partly blocked. This leads to a particularly stubborn form of CVI that can affect the deep venous system, sometimes requiring specialised treatment.

Common risk factors

• Family history of varicose veins or CVI
• Older age
• Female sex, especially after multiple pregnancies
• Pregnancy itself (often improves after delivery but can recur)
• Obesity, which increases pressure on the leg veins
• Jobs that involve long hours of standing or sitting
• Previous DVT or leg injury
• Smoking, which affects vein and skin health
• Tall stature

Many people have several of these factors. Having risk factors does not guarantee CVI, and not having them does not rule it out.

Signs and Symptoms to Watch For

If you already have a CVI diagnosis, knowing how the condition can progress helps you act early when something changes. Common symptoms include:

• Aching, heaviness, or a tired feeling in the legs, especially at the end of the day
• Swelling around the ankles and lower legs that improves overnight
• Itching or burning sensations over the lower leg
• Visible varicose veins — bulging, twisted veins under the skin
• Night-time leg cramps or restless legs
• Brown or reddish-brown discolouration around the ankle
• Dry, scaly, or eczema-like patches on the lower leg
• Hardening or tightening of the skin around the ankle (lipodermatosclerosis)
• A slow-healing wound near the inner ankle

Symptoms that should prompt a sooner-rather-than-later call to your doctor include sudden one-sided leg swelling and pain (which may indicate a new DVT), a new break in the skin that is not healing, signs of infection in a wound (spreading redness, warmth, pus, fever), or rapidly worsening skin changes.

How CVI Is Diagnosed

Diagnosis usually starts with a clinical history and a physical examination, and is confirmed with imaging.

Clinical examination

Your doctor will look at your legs while you are standing, since varicose veins and venous filling are more visible against gravity. They will check for swelling, varicose veins, skin colour changes, areas of hardened skin, and any wounds or scars from past ulcers. They will also feel your pulses to rule out arterial disease, which can mimic or coexist with CVI.

Duplex ultrasound

This is the central test for CVI. Duplex ultrasound is painless, uses no radiation, and combines a real-time image of your veins with measurement of blood flow direction and speed. The technologist will usually scan you standing or on a tilted bed, because reflux only shows up properly when blood is being pushed back by gravity.

• Which veins have failing valves (reflux)
• Whether any veins are blocked, narrowed, or have scarring from a previous DVT
• Whether the superficial veins, deep veins, or perforating veins (which connect the two systems) are involved

This map of the venous problem guides every treatment decision.

Other tests

In selected cases, additional imaging may be used:

• CT or MR venography: Detailed cross-sectional imaging used when blockage in the pelvic or abdominal veins is suspected, for example in suspected May-Thurner syndrome (compression of the left iliac vein).
• Intravascular ultrasound (IVUS): A miniature ultrasound probe used inside the vein, usually during a planned procedure on deep veins.
• Ankle-brachial index (ABI): A simple blood pressure comparison between arm and ankle to check for coexisting arterial disease, especially before prescribing strong compression.

Treatment and Management

Modern CVI care follows a layered approach. Conservative measures — lifestyle changes, compression, and skin care — are the foundation for almost everyone. Procedures are added when symptoms persist, when imaging shows treatable reflux, or when complications such as ulcers develop. Major society guidelines, including those of the Society for Vascular Surgery (SVS), the American Venous Forum (AVF), and the European Society for Vascular Surgery (ESVS), broadly support this stepwise framework.

Conservative measures

These are usually started first and continued lifelong, even after procedures.

• Leg elevation: Raising the legs above heart level for 15–30 minutes several times a day allows blood to drain by gravity, reducing pressure and swelling.
• Walking and calf exercises: Regular walking activates the calf muscle pump. Simple exercises like ankle pumps and heel raises help when you must sit or stand for long periods.
• Weight management: Reducing excess weight lowers the pressure load on the leg veins.
• Skin care: Daily moisturising helps protect the fragile skin of the lower leg. Keeping the skin clean lowers the risk of cellulitis (skin infection).
• Avoiding long static periods: Breaking up long flights, long drives, and long shifts on your feet reduces venous pressure spikes.

Compression therapy

Compression comes in several strengths, measured in mmHg. Lower strengths are used for mild symptoms; higher strengths are typically prescribed for advanced CVI or after ulcer healing. The right strength and fit are a clinical decision, partly because strong compression is not safe in people with significant arterial disease.

Multi-layer compression bandages are commonly used during the active treatment of venous ulcers, then replaced with stockings once the ulcer has healed.

Medications

No medication cures CVI, but some can help symptoms or wound healing:

• Venoactive drugs such as micronised purified flavonoid fraction (MPFF), horse chestnut seed extract, and others are used in some countries to reduce heaviness and swelling. Evidence is modest but supportive in major reviews.
• Pentoxifylline is sometimes added as an adjunct to compression for venous ulcer healing.
• Pain relief with simple analgesics may be used for symptomatic relief.
• Diuretics are generally not recommended for venous swelling alone, although they may be used for other coexisting conditions.

Endovenous thermal ablation

For superficial veins with significant reflux (most often the great saphenous vein and small saphenous vein), endovenous ablation has largely replaced traditional open vein stripping as the first-line procedure recommended in current SVS/AVF and ESVS guidelines.

The doctor inserts a thin catheter into the vein under ultrasound guidance, usually through a small puncture near the knee or ankle. The catheter delivers controlled heat — either from a laser fibre (endovenous laser ablation, EVLA) or a radiofrequency probe (radiofrequency ablation, RFA) — that seals the vein from the inside. The body then absorbs the closed vein over weeks to months, while blood reroutes through healthy veins.

The procedure is typically done under local anaesthesia with tumescent fluid (a dilute anaesthetic solution injected around the vein for comfort and protection). Most people walk out the same day and resume normal activity within a day or two.

Non-thermal, non-tumescent ablation

Newer options seal the vein without heat, removing the need for tumescent anaesthesia:

• Cyanoacrylate adhesive closure (medical glue) delivered through a catheter to bond the vein walls together.
• Mechanochemical ablation (MOCA), which combines mechanical irritation of the vein wall with a liquid sclerosant.

These approaches can be useful when the vein is in an awkward location or when tumescent injections are not ideal. The choice between techniques is made with the vascular specialist based on vein anatomy, symptoms, and available equipment.

Sclerotherapy

Sclerotherapy involves injecting a chemical — in liquid or foam form — into a vein to scar and close it. It is commonly used for:

• Spider veins and small reticular veins (liquid sclerotherapy)
• Smaller varicose veins or branches left after ablation (foam sclerotherapy)
• Ultrasound-guided foam treatment of certain deeper varicose veins, particularly in patients who are not candidates for thermal ablation

Sclerotherapy is done in the outpatient clinic and usually requires several sessions for the best result.

Ambulatory phlebectomy

Bulging varicose veins close to the surface can be removed through tiny skin nicks under local anaesthesia, in a procedure called ambulatory phlebectomy or microphlebectomy. It is often combined with ablation of the underlying refluxing vein during the same visit.

Open surgery: high ligation and stripping

Traditional surgery involves tying off (ligating) the saphenous vein near the groin and removing (stripping) the vein through small incisions. Once standard, this approach has been largely replaced by endovenous techniques in most settings because recovery is longer and bruising is greater. Open surgery still has a role in selected cases, such as unusual anatomy, very large veins, or where endovenous equipment is not suitable.

Deep venous interventions

When the deep veins themselves are blocked or narrowed — usually as a result of an old DVT or external compression such as May-Thurner syndrome — opening them up can dramatically reduce symptoms. This is typically done with venous angioplasty (a balloon to widen the vein) and a dedicated venous stent. These procedures are performed by vascular surgeons or interventional radiologists with specific expertise and are reserved for carefully selected patients.

Perforator vein treatment

Perforator veins connect the superficial and deep systems. When specific perforators near a venous ulcer show significant reflux on ultrasound, they may be closed with ablation or sclerotherapy as part of a comprehensive ulcer-healing plan.

Venous Leg Ulcers: A Special Focus

How ulcers are treated

• Multi-layer compression bandaging is the foundation of ulcer treatment and is supported by NICE and major vascular society guidelines. It is changed regularly by a trained nurse or wound care specialist.
• Wound dressings chosen for the type of ulcer (moist, dry, infected, sloughy) keep the wound clean and support healing.
• Treating the underlying reflux with endovenous ablation early in the ulcer course has been shown in randomised trials to speed healing and reduce recurrence; current guidelines support combining ablation with compression rather than compression alone.
• Infection management with antibiotics is used only when there is clear infection — not for routine ulcers, which are usually colonised with bacteria but not infected.
• Skin grafting may be considered for large or stubborn ulcers after the underlying venous problem has been treated.

After the ulcer heals

Lifelong daily compression stockings dramatically lower the risk of a new ulcer. Skin moisturising, prompt attention to any new break in the skin, and regular follow-up with the vein specialist are all part of staying ulcer-free.

Lifestyle and Self-Management

Because CVI is a long-term condition, what you do every day matters more than any single appointment. Habits that support healthy veins include:

• Wearing your compression as prescribed. Stockings only work when they are on. Putting them on first thing in the morning, before swelling builds up, makes them easier to wear and more effective.
• Moving regularly. A brisk daily walk, swimming, or cycling all activate the calf pump. If your job requires standing or sitting, set a reminder to move every 30–60 minutes.
• Elevating your legs. Whenever you sit for a while, prop your feet up. At night, raising the foot of the bed slightly can help.
• Caring for your skin. Daily moisturiser keeps the skin of the lower leg supple and less likely to crack. Check your legs regularly for new spots, scaly patches, or small wounds.
• Eating well and managing weight. A balanced diet supports skin health and helps with weight, which directly affects venous pressure.
• Quitting smoking. Smoking impairs wound healing and overall vascular health.
• Treating coexisting conditions. Diabetes, heart failure, and arterial disease all interact with CVI; keeping them well controlled helps your legs too.

Monitoring and Follow-up

How often you see your specialist depends on the stage of CVI and what treatments you have had. In general:

• Mild CVI (C1–C2) may be reviewed once a year or when symptoms change.
• After a vein procedure, a follow-up duplex ultrasound is usually performed within a few weeks to confirm that the treated vein is closed and that no clot has extended into the deep system.
• Advanced CVI (C4–C6) needs closer monitoring of skin changes and any ulcers, often with input from a wound care nurse.
• After deep venous stenting, regular ultrasound surveillance is standard to make sure the stent stays open.

Between appointments, paying attention to small changes — new swelling, new skin discolouration, or a wound that does not heal in a couple of weeks — helps catch problems early.

Complications of CVI

When CVI is not managed, or when it progresses despite treatment, several complications can develop:

• Venous ulcers, as discussed above.
• Superficial venous thrombosis (phlebitis): A painful, red, hard cord along a varicose vein caused by clotting in a surface vein. Sometimes it extends into the deep system, so it should be assessed by a doctor.
• Deep vein thrombosis (DVT): A clot in the deep veins, which can cause sudden swelling and pain and carries a risk of pulmonary embolism. People with CVI are at somewhat higher risk.
• Cellulitis: A bacterial skin infection that can take advantage of damaged skin. It usually causes spreading redness, warmth, and sometimes fever.
• Bleeding from a varicose vein: Occasionally a surface varicose vein can bleed, sometimes after a minor knock. Pressure and leg elevation usually control it; persistent bleeding needs medical attention.
• Reduced mobility and quality of life: Chronic pain, heaviness, and ulcers can affect work, sleep, and mood. This is a legitimate part of the condition, not something to push through alone.

Living with Chronic Venous Insufficiency

CVI is usually a lifelong condition, but it is one that responds well to consistent care. Most people are able to keep working, exercising, and travelling with some practical adjustments:

• Work: If your job involves long periods on your feet or seated, ask about a footstool, a sit-stand desk, scheduled breaks, or compression at work.
• Travel: On long flights or car journeys, wear compression stockings, walk every hour or two, and stay well hydrated.
• Exercise: Walking, swimming, cycling, and low-impact strength training are generally helpful. High-impact activities are fine for most people but discuss with your specialist if you have advanced CVI.
• Hot weather: Heat can worsen swelling. Cool showers, leg elevation, and air conditioning when possible can help.
• Emotional wellbeing: Visible leg changes, chronic discomfort, or dealing with ulcers can be distressing. Talking with family, friends, or a counsellor is a reasonable step, not a sign of weakness.

Preventing Progression

Even if you cannot completely undo existing damage, several steps can slow or stop CVI from getting worse:

• Stick with compression therapy, especially after a procedure or after a healed ulcer.
• Stay active and keep your calf muscles strong.
• Maintain a healthy weight.
• Treat varicose veins and reflux earlier rather than later if your specialist advises it; major guidelines now favour treating reflux in symptomatic patients sooner because it reduces the long-term risk of skin damage and ulcers.
• If you have had a DVT, follow your anticoagulation plan carefully — preventing further clot damage helps protect your venous valves.
• Have new symptoms assessed promptly rather than waiting them out.

When to Seek Urgent Care

Most CVI symptoms develop slowly and can be addressed at a routine appointment. However, some situations warrant prompt medical attention:

• Sudden swelling, pain, redness, or warmth in one leg, which could indicate a DVT
• Sudden shortness of breath, chest pain, or coughing up blood, which could indicate a pulmonary embolism — this is a medical emergency
• Heavy bleeding from a varicose vein that does not stop with pressure and leg elevation
• A spreading area of red, hot, painful skin with or without fever (possible cellulitis)
• A new ulcer or a rapid change in an existing one
• Severe pain in the leg that is out of proportion to your usual symptoms

Frequently Asked Questions

Is chronic venous insufficiency the same as varicose veins?

Not quite. Varicose veins are one visible sign of venous disease, but CVI refers to the underlying problem of high venous pressure and the wider range of symptoms it causes — swelling, skin changes, ulcers, and more. Some people with varicose veins do not have significant CVI, and some people with severe CVI have surprisingly few visible varicose veins.

Can CVI be cured?

CVI is generally managed rather than cured. Procedures such as ablation can permanently close the diseased veins that drive symptoms, and many people see major improvement. But the underlying tendency to develop vein problems often remains, which is why long-term self-care and follow-up matter.

Will my varicose veins come back after treatment?

The specific veins treated by ablation or surgery do not return, but new varicose veins can develop over time in other vein segments. Continuing with compression, exercise, and weight management lowers the chance of needing further treatment.

Are compression stockings really necessary if I have had a procedure?

For most people, yes — at least for a defined period after the procedure, and often longer-term, particularly if there are skin changes or a history of ulcers. The exact plan is a clinical decision based on your stage of CVI and what was done.

Can I have ablation in both legs at the same time?

Often yes, depending on the anatomy and your overall health. In some cases the specialist may prefer to treat one leg at a time, particularly when several veins need work or when you have other medical conditions.

Does pregnancy cause CVI?

Pregnancy increases blood volume and the pressure inside the pelvic and leg veins, and the hormones of pregnancy relax vein walls. Many women notice varicose veins or swelling during pregnancy that improve in the months after delivery. In some, however, pregnancy unmasks or accelerates a long-term tendency to CVI.

Can children get CVI?

CVI is overwhelmingly an adult condition. Children may have congenital vascular conditions that produce similar symptoms, but these are managed by specialised paediatric vascular teams and are quite different from typical adult CVI.

Is exercise safe with CVI?

For most people, regular exercise is one of the most helpful things they can do. Walking, swimming, and cycling activate the calf pump without straining the veins. If you have advanced CVI or an active ulcer, your specialist may suggest specific activity adjustments.

Do I need to avoid hot baths or saunas?

Heat can dilate veins and worsen swelling temporarily. Many people with CVI find that prolonged hot baths, saunas, or hot weather make their legs feel heavier. Cooling the legs afterwards and elevating them helps. Complete avoidance is not usually required.

Will losing weight really make a difference?

For people with excess weight, even modest weight loss reduces the pressure load on the leg veins, eases swelling, and improves the ability to exercise. Weight management is consistently part of CVI care in major guidelines.

Conclusion

Chronic venous insufficiency is common, slowly progressive, and very treatable. The condition itself is driven by a simple mechanical problem — valves that no longer hold blood against gravity — but its impact on daily life can be significant if it is not addressed.

Modern care offers a strong combination of tools: lifestyle changes that protect your veins every day, compression therapy that supports the calf pump and reduces swelling, and minimally invasive procedures that can close failing veins and dramatically ease symptoms. For people with skin changes or ulcers, structured wound care alongside vein treatment offers the best chance of healing and of staying ulcer-free.

Whether you are just starting compression therapy, considering a vein procedure, or managing an ulcer that has been part of your life for some time, the most important thing is to work with a specialist who knows your venous anatomy and to keep up with the daily habits that protect your legs over the long term.