What are varicose veins?
Varicose veins are enlarged, twisted veins that bulge visibly just beneath the skin surface, most commonly in the legs. They can look dark blue or purple and have a lumpy, cord-like appearance. Spider veins, which are much finer and closer to the surface, are a related but distinct condition.
Inside every vein there are one-way valves that keep blood moving in the right direction, up towards the heart. When these valves weaken or fail, blood flows backwards and collects in the vein. Over time, the pressure stretches the vein wall, causing it to bulge and become visible. This is called venous reflux, and it is the underlying cause of varicose veins.
Varicose veins are very common. The Edinburgh Vein Study, one of the most thorough population studies on the subject, found trunk varices in approximately 40% of men and 32% of women in the general population. They are not simply a cosmetic concern: many people experience real symptoms, and left untreated over years, they can progress to cause more significant problems with the skin and circulation.
What causes varicose veins?
The most important underlying cause is a weakness in the wall of the vein or its valves, which can be inherited. If a parent had varicose veins, you are more likely to develop them too. Other factors that increase the risk include:
- Age: veins naturally lose elasticity over time, making valve failure more likely
- Pregnancy: increased blood volume and pressure from the growing uterus puts extra strain on leg veins
- Standing for long periods: jobs that involve prolonged standing can increase the workload on leg vein valves
- Previous deep vein thrombosis (DVT): damage to deeper veins can cause secondary varicose veins
- Obesity: increases abdominal pressure, making it harder for blood to return from the legs
Varicose veins are not caused by crossing your legs, wearing tight clothing, or sitting too much, despite common beliefs. These things do not damage vein valves.
Diagram: how varicose veins develop
Diagram for illustration only. Not a clinical image.
What symptoms do varicose veins cause?
Not everyone with varicose veins has symptoms. However, when symptoms do occur, they typically include:
- Aching, throbbing or heaviness in the legs, particularly after standing for a while
- Swelling around the ankles by the end of the day
- Itching around the affected veins
- A burning or cramping sensation in the legs, especially at night
- Skin that feels tender directly over a varicose vein
Symptoms are typically worse in hot weather and after long periods of standing, and tend to improve with walking and elevating your legs.
When should I see a doctor?
Many people live with varicose veins without needing treatment. However, there are clear situations where specialist assessment and treatment are appropriate, and NICE guideline CG168 sets these out.
You should be referred to a vascular service if you have varicose veins with any of the following:
- Symptoms such as pain, aching, heaviness, itching or swelling (even if mild)
- Skin changes around the ankle, including discolouration, eczema or hardening of the skin
- A superficial vein thrombosis (a painful, hard, red vein)
- A venous leg ulcer (a break in the skin below the knee that has not healed within two weeks)
- A healed venous leg ulcer
- Bleeding from a varicose vein
NICE guidance is clear that compression stockings should not be offered as an alternative to specialist referral for people who meet these criteria.
How are varicose veins assessed?
At a specialist vascular assessment, the surgeon will take a full history, examine your legs, and perform a duplex Doppler ultrasound scan. This is a painless scan that uses sound waves to map the blood flow in your veins and identify exactly where the valves are failing.
The duplex scan is essential. It shows which veins are responsible for the reflux, how far up the leg the problem extends, and whether any of the deeper veins are involved. This information is what guides the choice of treatment. Treating varicose veins without a duplex scan is not appropriate, as it is not possible to know which veins need to be addressed.
The findings are typically described using the CEAP classification, which grades venous disease from C0 (no visible disease) to C6 (active venous ulcer). This helps to standardise communication between clinicians and to track how the condition changes over time.
What are the treatment options?
Treatment for varicose veins has changed significantly over the past 20 years. Surgery, which was once the standard approach, has largely been replaced by minimally invasive techniques performed under local anaesthetic as a day case. NICE guideline CG168 recommends a clear order of preference based on evidence of effectiveness.
Endothermal ablation: laser (EVLA) and radiofrequency (RFA)
Endothermal ablation is the recommended first-line treatment for most people with varicose veins and reflux in the main trunk veins. It works by delivering heat energy directly inside the vein through a very thin probe, causing the vein wall to collapse and seal shut. The treated vein is then gradually absorbed by the body over the following weeks.
There are two main forms: endovenous laser ablation (EVLA), which uses laser energy, and radiofrequency ablation (RFA), which uses radiofrequency waves. Both are highly effective. Studies show vein closure rates of approximately 91 to 92% at two years for both techniques.
The procedure is done under local anaesthetic, takes around one hour, and you walk out of the clinic afterwards. Most people return to desk work within one to two days and to more physical activity within a week. Bruising and some tightness along the treated vein are common in the first two to three weeks and settle on their own.
Ultrasound-guided foam sclerotherapy
If endothermal ablation is not suitable, NICE recommends ultrasound-guided foam sclerotherapy as the next option. A chemical agent (sclerosant) is mixed with gas to create a foam, which is then injected directly into the affected vein under ultrasound guidance. The foam irritates the inner lining of the vein, causing it to close down.
Foam sclerotherapy is particularly useful for veins that are too tortuous or small for a laser probe, for recurrent varicose veins, and for treating smaller tributary veins. It may need to be repeated more than once to achieve the best result. It is also done as a day case under local anaesthetic.
Surgery (ligation and stripping)
Surgical ligation and stripping of the great saphenous vein is now less commonly used since the development of endothermal techniques. It remains an option for patients in whom the minimally invasive treatments are not suitable, and it can produce good long-term results. Surgery is done under general or spinal anaesthetic and requires a longer recovery period of two to four weeks.
Phlebectomy
Phlebectomy involves removing the visible surface varicose vein branches through tiny puncture wounds in the skin, each no larger than 2 to 3 mm. It can be performed at the same time as EVLA or RFA, or as a standalone procedure for smaller residual veins. It is done under local anaesthetic and leaves very small marks that usually fade to become barely visible.
A note on compression stockings
Compression stockings can help to relieve the symptoms of varicose veins by supporting the vein wall and reducing swelling. However, they do not treat the underlying problem and are not a substitute for intervention. NICE guideline CG168 states clearly that compression stockings should not be offered to treat varicose veins unless interventional treatment is unsuitable. If compression bandaging or hosiery is used after a procedure, it should be worn for no more than seven days, as there is no evidence of benefit beyond this point.
Risks and what to expect after treatment
Modern endovenous treatments are well tolerated and recovery is often quick, but no procedure is without risk. It is important to discuss the following with your surgeon before treatment, as individual results vary:
- Bruising and tenderness along the treated vein, usually settling over one to two weeks
- Skin staining or pigmentation over the treated area, which usually fades but can occasionally persist
- Thrombophlebitis (inflammation of a treated vein), which can cause a tender, firm cord under the skin
- Nerve irritation causing temporary numbness or tingling near the treated area
- Recurrence of varicose veins or development of new veins over time
- Rarely, deep vein thrombosis (DVT) or pulmonary embolism (PE), which are uncommon but serious; your team will discuss ways to reduce this risk
Treatment outcomes are generally good and most people are satisfied, but cosmetic results cannot be guaranteed and further treatment is sometimes needed.
Thread veins and spider veins: cosmetic treatment
Thread veins, also called spider veins or telangiectasias, are the fine red, blue or purple lines that appear just beneath the skin surface. They are smaller than varicose veins, typically less than 2 mm in diameter, and branch out in a web-like pattern most often on the thighs, calves and ankles.
Thread veins do not usually cause medical problems, but for many people they are a source of real self-consciousness. They affect the great majority of adults to some degree, and they are one of the most common reasons people seek a private vascular consultation.
It is important to understand that thread veins are almost never treated on the NHS, as they fall below the NICE CG168 referral threshold. Private treatment is the appropriate route for most patients.
Microsclerotherapy
Microsclerotherapy is the most effective treatment for thread veins and spider veins on the legs. A very fine needle is used to inject a small amount of sclerosant solution directly into each thread vein. The chemical irritates the inner lining of the vein, causing it to collapse, seal shut, and gradually fade from view over the following weeks.
Because the veins being treated are so small, the needle used is extremely fine and the injections are largely painless. A magnifying loop and bright light are used to ensure precision. Sessions typically last 30 to 45 minutes. Most people need two to three sessions spaced several weeks apart to achieve the best result, with studies showing up to 80% improvement in thread vein appearance after a course of treatment.
Compression stockings are worn after treatment to support the treated veins and reduce the risk of staining. Successfully treated thread veins usually fade, although new thread veins can develop over time, though new ones may develop over time given the underlying tendency of vein walls to weaken with age.
Advanced endovenous techniques: what private treatment offers
Private vascular care gives access to the full range of modern endovenous techniques, including newer approaches that are not yet available through most NHS services. Understanding the differences helps you make an informed choice.
EVLA (endovenous laser ablation)
EVLA uses laser energy delivered through a very thin fibre placed inside the vein to generate heat, causing the vein wall to collapse and seal. It is highly precise and can treat veins of varying sizes and anatomy. The procedure is performed under local tumescent anaesthetic (a dilute solution injected around the vein to numb it and protect surrounding tissue). EVLA is one of the most widely studied techniques and has an excellent long-term track record, with published two-year closure rates of approximately 91 to 92%.
Most patients experience some bruising and a pulling sensation along the treated vein for two to three weeks. Return to desk work is typically possible the next day, and to more physical activity within a week. Compression stockings are worn for up to seven days after treatment.
RFA (radiofrequency ablation)
RFA uses radiofrequency energy rather than laser to heat and seal the vein. The technique is similar to EVLA and achieves comparable closure rates. Some studies report slightly less post-procedure bruising and pain with RFA compared to older laser protocols, though modern EVLA systems have narrowed this difference considerably. Like EVLA, RFA is performed under local anaesthetic as a day case, and most people are walking normally within hours of the procedure.
Cyanoacrylate glue closure (VenaSeal)
VenaSeal is a newer technique in which a small amount of medical-grade cyanoacrylate adhesive (similar in principle to surgical glue) is delivered inside the vein through a catheter, sealing it shut without the use of heat. Because no heat is involved, there is no need for the tumescent local anaesthetic injected around the vein that EVLA and RFA require, making the procedure more comfortable for most patients.
A key practical advantage is that compression stockings are not required after VenaSeal, which means patients can return to normal activities, including exercise, more quickly than with thermal techniques. This makes it particularly suited to patients with active lifestyles or those who find compression stockings difficult to tolerate.
Published evidence is strong. A large multicenter retrospective study of over 800 veins treated with VenaSeal reported closure rates of 99.3% at four months and 97.2% at 16 months, with no cases of symptomatic DVT. A network meta-analysis reported 94.8% closure at 6 months and 89% at 12 months across the published literature. At five years, closure rates of 91.1% have been reported in retrospective cohorts. The main specific risk is a delayed hypersensitivity reaction to the glue, which occurs in a small number of patients and is usually mild and self-limiting.
Ultrasound-guided foam sclerotherapy
Foam sclerotherapy uses a sclerosant chemical mixed with gas to create a foam that is injected directly into the vein under ultrasound guidance. The foam is more effective than liquid sclerosant at displacing blood and making contact with the vein wall, which makes it the preferred technique for medium-sized veins that are too small for a laser or radiofrequency catheter but too large for microsclerotherapy.
It is commonly used to treat residual tributary veins after EVLA or RFA, for recurrent varicose veins, and as a standalone treatment where the anatomy is suitable. Multiple sessions may be needed. It is performed as a day case under no anaesthetic or with minimal local anaesthetic. Return to normal activity is usually immediate.
Choosing between techniques
The right treatment depends on the size and position of the veins, the anatomy found on duplex scan, your lifestyle, and your personal priorities. At a specialist vascular consultation, the options will be discussed with you based on your specific scan findings. Many people have more than one technique used in the same or subsequent sessions: for example, EVLA or VenaSeal to treat the main trunk vein, foam sclerotherapy for smaller tributaries, and microsclerotherapy for any residual thread veins.
The goal is always to treat the root cause first (the underlying reflux) before addressing the surface appearance. This gives the best and most durable result.
What happens if varicose veins are left untreated?
For many people, varicose veins remain a source of discomfort without progressing to more serious problems. However, over years, untreated venous reflux can lead to:
- Chronic skin changes around the ankle, including discolouration, eczema and hardening of the skin (lipodermatosclerosis)
- Venous leg ulcers, which are wounds that form around the ankle and can be very slow to heal
- Superficial vein thrombosis, where a clot forms within a varicose vein, causing a painful, inflamed cord under the skin
- Bleeding from a varicose vein close to the skin surface
Treating varicose veins before these complications develop is generally easier and produces better outcomes than treating them after skin damage has occurred.
What to do next
If your varicose veins are causing any of the symptoms described in this guide, it is worth having a specialist assessment. A duplex ultrasound scan and a consultation with a vascular surgeon will clarify what is happening, which veins are responsible, and what your treatment options are. You do not need a GP referral for a private appointment.
Treatment for varicose veins is highly effective. The large majority of people who are treated with EVLA or RFA experience a significant improvement in their symptoms and are very pleased with the results.
Sources and further reading
- NICE CG168. Varicose veins: diagnosis and management.
- NHS. Varicose veins.
- ESVS Clinical Practice Guidelines on the Management of Chronic Venous Disease.