Chronic venous insufficiency: what it is and how it shows up

2026-11-05

• CVI develops when the vein valves and the calf muscle pump struggle to move blood out of the legs.
• Typical signs are evening heaviness, tiredness and swelling, night cramps, visible veins and skin changes near the ankles.
• The condition usually progresses slowly, and seeing a phlebologist early helps slow it down.
• Treatment is built on movement, weight control and compression prescribed by a doctor.
• Sudden swelling and pain in one leg or breathlessness is a reason to call an ambulance (103) at once.

A shop assistant at the corner store, a teacher after six lessons, a driver back from the run between Tashkent and Fergana — by evening they all describe something similar. Their legs throb as if filled with lead, sock elastic leaves a deep groove, and at night a calf cramps. Most people put it down to tiredness, age or the heat.

Sometimes that is all it is. But when these feelings return day after day, they may point to chronic venous insufficiency — one of the most common conditions affecting the leg veins. Here is what it is, how it shows up and why a visit to the doctor is worth not putting off.

What is chronic venous insufficiency?

Blood travels from the legs back to the heart against gravity. Two things help it: valves inside the veins, which let blood flow only upwards, and the calf muscles, which squeeze the veins with every step and push blood up like a pump.

When the valves no longer close tightly and the vein walls stretch, some blood slips back down. Pressure in the leg veins rises, blood pools, and fluid seeps into the tissues. This is how chronic venous insufficiency (CVI) develops — impaired drainage of blood from the lower limbs that, over time, changes not only the veins but the skin as well.

A quick note on terms. Doctors call the whole spectrum of these problems chronic venous disease. In the international CEAP classification, chronic venous insufficiency usually refers to the more advanced stages — with swelling, skin changes or ulcers. In everyday speech and in many medicine leaflets, however, CVI is used for any sign of blood pooling in the legs.

Why does CVI develop?

There is rarely a single cause; usually several factors add up.

• Family history — weak vein walls and valves often run in families.
• Long hours standing or sitting still: behind a counter, in a workshop, at a computer or behind the wheel.
• Pregnancy and hormonal changes — one reason vein problems are more common in women.
• Age: vein walls lose elasticity over the years.
• Excess weight and an inactive lifestyle.
• A previous deep vein thrombosis — the valves may remain damaged afterwards.

How does chronic venous insufficiency show up?

The symptoms are deceptive because they build up gradually. Many people get used to them over the years and think they are normal. Pay attention if:

• your legs feel heavy, tired, tight or achy by evening;
• your ankles and shins swell, and the swelling eases or disappears by morning;
• your calves cramp at night or your legs cannot settle — this can be restless legs syndrome;
• the skin on your shins itches, especially in hot weather;
• you feel better after walking or lying down with your legs raised.

Some signs are visible: spider veins and fine networks of veins, twisted bulging veins and, in later stages, darkening of the skin around the ankles, dryness and flaking, and hardening of the tissues. Typically, complaints get worse in summer, after long periods of standing and towards the end of the working day.

What are the stages of CVI?

Doctors around the world describe vein disease using the CEAP classification. Its clinical part divides changes into classes from C0 to C6:

• C0 — no visible changes, although there may be symptoms;
• C1 — spider veins and reticular veins;
• C2 — varicose veins;
• C3 — oedema (swelling);
• C4 — changes in the skin and the tissue beneath it: pigmentation, eczema, hardening;
• C5 — a healed venous ulcer;
• C6 — an open venous ulcer.

The condition does not have to pass through every stage, and in many people it stays in the early classes for years. The sooner you start looking after your veins, the better your chances of staying there. Read more about each class in CEAP classification explained simply.

How does a doctor make the diagnosis?

Leg veins are the field of a phlebologist or vascular surgeon, although you can start with a GP. The doctor will ask about your symptoms, examine your legs while you stand and, if needed, refer you for a duplex ultrasound scan. This painless test shows how the valves work, whether blood flows backwards and whether there are any clots. We described what to expect in our article on leg vein ultrasound.

Remember that swollen legs are not always caused by veins. Heart, kidney or thyroid disease and the side effects of some medicines can all be responsible. That is why it is best not to diagnose yourself from symptoms alone.

What helps with chronic venous insufficiency?

Treatment is always tailored to the person, but the foundation is the same for everyone.

1. Movement. Walking, swimming, cycling and calf exercises switch on the calf muscle pump.
2. Rest with your legs raised — 15–20 minutes several times a day, with your legs slightly above heart level.
3. Breaks from sitting or standing work: every 45–60 minutes, walk around or rise onto your toes 10–15 times.
4. Weight control and moderation with salt.
5. Compression stockings — if your doctor recommends them. The specialist chooses the compression class, and compression is not suitable for some arterial diseases.

If varicose veins are pronounced, your doctor may discuss minimally invasive procedures. To relieve symptoms such as heaviness, pain and swelling, international guidelines allow venoactive medicines alongside the core measures.

Phlebodia 600 (diosmin 600 mg) is an over-the-counter venotonic medicine. According to its leaflet, it is indicated to relieve symptoms of lymphovenous insufficiency of the lower limbs: heaviness and tiredness in the legs, pain and restless legs syndrome. The usual dose is 1 tablet a day with a meal, and a course typically lasts 2 months. If symptoms do not ease within 2 weeks, see a doctor. Contraindications and other details are in the official instructions. Before use, read the instructions and consult a specialist.

When do you need urgent help?

CVI itself develops slowly. But complications can arise against its background, and some of them need immediate action.

The warning signs of vein inflammation are covered in detail in our article on thrombophlebitis symptoms.

The bottom line

Chronic venous insufficiency is not a life sentence or a reason to panic. It is a signal to pay closer attention to your legs. Daily walks, breaks at work, comfortable shoes and a timely visit to a phlebologist help keep your legs light for years and prevent complications. Start small: tonight's evening walk is already a step in the right direction.

Sources: 1. De Maeseneer MG, Kakkos SK, Aherne T, et al. ESVS 2022 Clinical Practice Guidelines on the Management of Chronic Venous Disease of the Lower Limbs. Eur J Vasc Endovasc Surg. 2022;63(2):184–267. 2. Lurie F, Passman M, Meisner M, et al. The 2020 update of the CEAP classification system and reporting standards. J Vasc Surg Venous Lymphat Disord. 2020;8(3):342–352. 3. Instructions for medical use of Phlebodia 600 (Republic of Uzbekistan).

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