What is CVI? Chronic venous insufficiency grades and CEAP explained
Chronic venous insufficiency is not a separate disease but poor blood return from the leg veins. A vascular surgeon explains what "CVI grade 2" and "C2s" mean in a report and why the treatment plan depends on ultrasound, not on a number.
Chronic venous insufficiency (CVI) is not a separate disease. It is a condition in which the leg veins struggle to return blood to the heart, so blood pools in the lower legs. The most common cause is varicose vein disease; less often it is the after-effect of a deep vein thrombosis. The CVI grade (1, 2, 3) or the CEAP class (C0-C6) tells you how much the tissues of the leg are affected, but not whether you need a procedure: that is decided by a venous ultrasound.
A familiar situation: after a check-up in a local clinic, or a medical exam for work or a visa, your report says "Varicose disease. CVI grade 2" or "CVI C2s". Nobody explained it, and an internet search shows frightening photos of leg ulcers. Below I decode these entries the same way I explain them to patients in my office.
What is venous insufficiency in simple terms?
Blood from the legs travels upward against gravity. The calf muscles pump it up as you walk, and valves inside the veins stop it from sliding back down. When the valves no longer close properly, or the vein is stretched, some of the blood flows back down. This backward flow is called reflux. Pressure in the lower-leg veins stays high, especially when you stand and towards the evening.
Causes of venous insufficiency
- varicose vein disease: widened veins under the skin with leaking valves, the most common cause;
- post-thrombotic syndrome: the after-effects of a deep vein thrombosis, when the valves are damaged or the vein is narrowed;
- less often, congenital features of the veins or compression of a vein from outside.
Symptoms of venous insufficiency: an evening self-check
CVI symptoms build up during the day, so check yourself in the evening. Do you have:
- heaviness, a bursting feeling or an aching pain in the lower legs that eases if you lie down with your legs raised;
- a dent that stays after you press a finger into the skin above the inner ankle for a few seconds, or deep marks from sock elastic;
- swelling that is still there in the morning;
- night cramps and itchy skin on the shins;
- darkening, flaking or hardening of the skin above the ankle.
Heaviness and evening swelling that goes away overnight usually correspond to CVI grade 1; morning swelling and skin changes correspond to grade 2. This is a rough guide, not a diagnosis. Swelling can also come from heart or kidney disease or from lymphedema, so the cause is confirmed by an examination and an ultrasound.
How CVI differs from varicose veins
Varicose veins are the disease, the cause. CVI is the consequence: how that cause affects the leg. That is why a full diagnosis usually has two parts. First comes the disease ("Varicose disease of the lower limbs"), then the state of blood return ("CVI grade 1" or a CEAP class).
Strictly speaking, the umbrella term in guidelines is "chronic venous disease", and "venous insufficiency" refers to the stages with swelling, skin changes or an ulcer (C3-C6). In everyday practice, though, doctors in Uzbekistan and other post-Soviet countries write "CVI" in almost every venous diagnosis, and this is not considered a mistake.
CVI grades and classification: what 1, 2, 3 and C0-C6 mean
The CVI grading system comes from Russian phlebology. Many doctors in Uzbekistan and neighbouring countries still write the diagnosis this way, alongside CEAP or instead of it. If you were seen at home in Europe or the US, you are more likely to have seen CEAP only.
CEAP is the international classification used in European (ESVS) and Russian guidelines. In local reports it is sometimes written in Cyrillic letters that look almost the same. Usually the report shows the letter C with a number: C0 means no visible changes, C1 spider veins and thread veins, C2 varicose veins, C3 swelling, C4 skin changes, C5 a healed ulcer, C6 an open ulcer. In the short version the class is set by the most advanced sign; sometimes all findings are listed, for example "C2,3", meaning varicose veins plus swelling.
The letter after the number: s means there are symptoms (heaviness, pain, cramps, itching), a means there are none, r means recurrence after treatment. Sometimes the full formula is written, for example "C2s Ep As Pr": symptomatic varicose veins, primary, that is, not caused by a clot (Ep), in the superficial veins (As), with reflux (Pr). Es means a secondary cause, most often a past thrombosis, Ad means the deep veins are involved, and Po means the vein is blocked.
The two systems do not match one to one, so the correspondence is approximate:
| CVI grade in the report | What is usually seen on the leg | Approximate CEAP class |
|---|---|---|
| CVI 0 | Spider veins, thread veins or varicose veins; no swelling and no symptoms | C1-C2, often with the letter a |
| CVI 1 | Heaviness by evening, swelling that goes away overnight | C0s-C2s; with evening swelling, C3 |
| CVI 2 | Swelling persists in the morning; darkening, eczema or hardening of the skin above the ankle | C3-C4 |
| CVI 3 | A venous leg ulcer, healed or open | C5 (healed), C6 (open) |
The CVI grade is not the same as the stage of varicose veins and says nothing about the size of the veins. Large bulging veins can come with CVI 0-1, and darkened skin can appear with barely visible veins. I describe how the disease itself progresses in the article Stages of varicose veins.
If the entry is needed for a military or occupational medical board, for example "CVI grade 2", fitness is decided by that board after a full examination, not by a single line in a report. I explain what matters for the board in the article Varicose veins and military service.
What does "varicose veins, CVI C2" mean?
It means you have varicose veins, but the doctor found no swelling and no skin changes. At this level, treatment, if needed, is usually simpler than once the skin has changed. Nothing about this entry is urgent. But the conclusion "it will go away on its own" is wrong too: varicose veins do not disappear by themselves, so a plan is worth making based on ultrasound.
Why a diagnosis without ultrasound is incomplete
The C class is assigned by examining the leg, but an examination cannot show where the excess pressure in the leg comes from. That is what a duplex venous ultrasound shows:
- which veins are failing: the great or small saphenous vein, their tributaries, the perforator veins;
- whether there is reflux and how long it lasts; in superficial veins, backward flow lasting longer than 0.5 seconds is usually considered abnormal;
- whether the deep veins are open and whether there are signs of a past thrombosis;
- whether there is a fresh clot.
Two legs with the same "C2" entry may need different things: one has reflux along the trunk of the great saphenous vein, the other only along a tributary. I explain what the numbers in an ultrasound report mean in the article Reflux on a venous ultrasound: what it means.
Treatment of CVI in the legs: what is discussed at each class
I make a specific plan after an examination and an ultrasound. In general terms, the logic is this:
- C0-C1: as a rule, observation and lifestyle measures. Spider veins are treated by choice, if they bother you.
- C2: if the ultrasound shows reflux and the veins cause symptoms, removing the reflux is discussed, usually with a minimally invasive method such as endovenous laser ablation (EVLA) or sclerotherapy. If there are no symptoms, observation with a follow-up ultrasound is possible.
- C3-C4: besides treating the cause, regular compression and skin care matter. Skin changes are a reason not to postpone a decision.
- C5-C6: the foundation is wound care and compression, and according to current guidelines, removing the reflux helps an ulcer heal faster and come back less often. Before compression, especially with an ulcer, diabetes, smoking or a weak pulse in the foot, the leg arteries must be checked: if they are severely narrowed, tight stockings and bandages are dangerous.
Venoactive drugs, for example diosmin-based preparations, may reduce heaviness and swelling, but they do not remove reflux and do not make varicose veins disappear. It is better to start them after a consultation.
Myth: "CVI grade 2 always means surgery"
Not true. The CVI grade describes the state of the leg, not the extent of treatment. The indications are based on the whole picture: symptoms, class, ultrasound findings and general health. The decision is made together with the patient, not by a single number.
The second myth is that CVI can only get worse. If reflux is dealt with in time and compression is worn, swelling and heaviness usually decrease, and skin changes can be slowed down. Pigmentation and hardening that have already formed may only partly fade, so it is better not to let things get that far.
When to see a doctor urgently
Whatever your report says, do not wait for a routine appointment if:
- one leg suddenly swells, especially with pain or a bursting feeling in the calf: this can be a deep vein thrombosis;
- you develop shortness of breath, chest pain or cough up blood: call an ambulance immediately (103 in Uzbekistan);
- both legs swell and at the same time you become short of breath, especially lying down, or gain weight quickly: a heart or kidney cause needs to be ruled out urgently;
- a vein becomes red, firm and painful: this may be thrombophlebitis;
- redness on the shin spreads quickly, the leg feels hot and you have a fever: this may be erysipelas, and you need to be seen the same day;
- a weeping wound or an ulcer appears on the shin;
- the foot becomes cold and pale, the leg hurts at rest or at night, or dark patches appear on the toes: this may be a problem with arterial blood flow, and compression should not be worn until you are examined;
- a varicose vein is bleeding: press on the bleeding spot, raise the leg and call an ambulance.
Do not massage or warm a painful, firm vein, and do not put random creams or ointments on a leg wound before a doctor has seen it.
Questions to ask your doctor about the report
Bring the report to your appointment and ask five questions:
- 1What is my CEAP class, and which sign is it based on?
- 2Where exactly is the reflux: in which vein, at what level and how long does it last?
- 3Are the deep veins open, and are there any signs of a past thrombosis?
- 4What happens if we just observe for now, and when should the ultrasound be repeated?
- 5Do I need compression stockings, which class, and when should I wear them?
If your ultrasound was done long ago or the report does not describe reflux, it makes sense to repeat the examination. You can send your report for an online consultation as a second opinion, but I make the final decision about treatment after an ultrasound.
Key takeaways
CVI describes how well your veins cope with returning blood. It is not a verdict and not a referral for surgery. The grade or CEAP class shows how much the leg tissues are affected, while the cause and the plan come from a venous ultrasound. The earlier the picture is clear, the more gentle options there are to choose from.
Frequently Asked Questions
What is CVI?
CVI stands for chronic venous insufficiency: the leg veins struggle to return blood to the heart, so it pools in the lower legs. It shows up as heaviness, swelling, skin changes and, in severe cases, an ulcer. The most common cause is varicose vein disease, less often the after-effects of a thrombosis.
Is CVI grade 2 serious?
It usually means that the swelling has become persistent or that skin changes have appeared: pigmentation, eczema or hardening. This is a reason not to postpone a venous ultrasound and a discussion of treating the cause. But it is not an emergency and not an automatic indication for surgery.
What should I do about CVI grade 1?
CVI grade 1 usually means heaviness and swelling that comes by evening and passes overnight. It is worth having a venous ultrasound to find the cause, walking more and avoiding long periods of sitting still. Compression should be chosen by a doctor.
Does CVI grade 2 affect fitness for military service?
Fitness is decided only by the military medical board under the current regulations, not by a phlebologist and not by a line in a report. The board looks at whether persistent swelling and skin changes are confirmed by examination and venous ultrasound, and whether there has been a thrombosis or an ulcer. Bring the ultrasound report and a vascular surgeon's conclusion.
What does "varicose veins, CVI C2" mean?
C2 in the international CEAP classification means there are varicose veins, but no swelling, skin changes or ulcers. The letter s after the number means the veins cause symptoms, a means there are none. Treatment is decided by ultrasound: where the reflux is and how pronounced it is.
Can chronic venous insufficiency be cured?
Treatment targets the cause: removing reflux in failing veins, choosing compression, and caring for the skin and any wound. After that, swelling and heaviness usually decrease, but no one can promise the veins will never change again. Some CEAP signs remain after treatment: a healed ulcer is recorded as C5, and established skin changes as C4, while the class based on the veins themselves is reassessed.
This article is for informational purposes only and does not replace a consultation with a qualified physician. If you are experiencing symptoms, please see a specialist.