Leg Spider Veins and Thread Veins

Leg spider veins are unsightly vessels in the skin up to 1 mm in size. Also known as thread veins or broken veins, the medical term for these veins is telangiectasia.

Doctors and nurses as well as the public often regard leg spider veins as just cosmetic, trivial in nature and of no health consequence. For this reason, many people with leg spider veins seek treatment in a cosmetic clinic or sometimes in a beauty salon.

But of course, vein specialists know that leg spider veins are never just cosmetic.

  • Recent research confirms the importance of identifying and treating the underlying cause of the spider veins (feeder veins with incompetent valves)
  • Treatment involves the injection of prescription medicine into the veins


For these reasons, people with leg spider veins should be carefully assessed and have proper medical investigations before treatment and the injection should be carried out by properly trained healthcare professionals who are competent  and how are regulated to prescribe medicines (doctors, nurses and independent prescribers).

What do leg spider veins look like?

Spider veins have a typical appearance and most people instantly recognise them. They can occur anywhere on the leg but they are frequently found on the outer thigh, inner calf and around the ankle.

What causes leg spider veins?

In my practice, the majority of people asking for advice or treatment are women. Of course, men get them too, but because men have hairy legs and tend to wear trousers, spider veins are of more concern to women than to men. 

Young women with no symptoms may have no underlying issues with the veins underneath the skin and in this situation, the spider veins are said to be “idiopathic”. Women who have symptoms such as leg throbbing, swelling or leg discomfort, usually have underlying vein problems or even varicose veins. In this situation, the spider veins are said to be “secondary”. This is an important point, because people with idiopathic spider veins can have injection treatments pretty much straight away, whereas, people with secondary spider veins are best advised to have a leg check up with an ultrasound scan.

In my experience, idiopathic Leg Spider Veins are very rare and a duplex ultrasound scan is advisable in all cases.


When are spider veins a problem?

For most people, it is the unsightly appearance of the spider veins that causes embarrassment, poor self-esteem and lack of confidence. This is often the motivation for seeking help. For others, symptoms such as leg ache, throbbing and swelling may cause concern. 

Spider Veins around the ankle

Spider veins around the ankle may indicate a major problem with the function of veins below the skin and these spider veins should always be taken seriously. These veins are called “Corona Phlebectatica” also known as ankle flare. So spider veins around the ankle may actually be a health problem.

Spider veins around the ankle may also indicate that the skin is being damaged by a faulty vein circulation. In this situation, the skin becomes thin and white and it is particularly vulnerable to injury and ulceration. In fact, spider veins around the ankle (corona phlebectatica) in association with “atrophie blanche” are warning signs of the risks of developing a leg ulcer


What Tests are needed before Leg Spider Veins are treated?

Success when treating leg spider veins depends on careful patient selection. That means excluding unsuitable patients based on health criteria, unsuitable types of leg spider veins based on the causes and advising people who might be expecting “perfection.” 

People suitable for Microsclerotherapy are selected after a history, examination special tests such as Duplex Ultrasound, Near Infra-red Imaging, Cross-Polarised Photography and Transillumination.

Inclusion Criteria 

  • Healthy patients 
  • Healthy skin with no pigmentation or signs of chronic venous insufficiency
  • No varicose veins 
  • No leg or ankle swelling 
  • No contraindications 
  • No evidence of superficial venous reflux 

How can Spider Veins be treated?

People with no symptoms, no ankle flare or varicose veins and a normal scan can be treated by Micro-injections (Microsclerotherapy). Microsclerotherapy involves the injection of a prescription medicine into the vein.

Microsclerotherapy is  a very delicate injection procedure and requires skill and accuracy. The prescription medicine is called a sclerosant. It works by removing the delicate lining of the spider veins and a healing process starts which causes the vein to fade and disperse.

What are Feeder Veins?

Leg spider veins are situated in the skin. They are 1 mm in size and because they are located in the skin they are easily visible. Because no one likes the look of leg spider veins, it is easy to forget that in nearly 90% of people with leg spider veins, an underlying deeper problem can be identified as the cause. Although it is tempting just to inject them this is very rarely the right way to proceed.

We now know that the spider veins in the skin are connected to deeper veins. We also know that veins have delicate folds in the lining which open and close to keep blood flowing in the correct direction. These delicate folds are called valves. They are easily seen in the larger veins on ultrasound. However in the smaller veins these valves cannot be easily detected. It has only been as a result of detailed research over many years that we now understand that even small veins just under the skin have these delicate folds and one-way valves. Because the vessels are so small, they are called microvalves.

The blood in the spider veins in the skin drains into deeper veins called reticular veins. Under normal circumstances, these reticular veins carry blood away from the spider veins.

However if microvalves do not work properly, there can be a back pressure of blood  and this causes the spider veins to appear. In this situation, the reticular veins become feeder veins.

If these feeder veins are not treated, then injecting the spider veins directly is either likely to be ineffective or it can actually make the spider veins look worse.

What are the Results of Leg Spider Vein Treatment?

Microsclerotherapy has been studied in several large Randomised Controlled Trials and improvement of more than 90% is achieved at the end of treatment. The European Guideline Group has recommended that liquid sclerotherapy is the method of choice for the treatment of C1 telangiectasias and reticular veins.

Sclerotherapy depends on a healing process that takes time. The results are not instant. 

What are the Risks of Leg Spider Vein Treatment?

Serious complications such as Deep Vein Thrombosis (DVT or clots), allergic reactions or infection are very rare (very much less than 1 in a 1,000 risk). 

Some pain or stinging may occur at the injection sites and some patients experience restlessness in their legs during the first few nights. 

For a month or so the veins may appear more prominent and the injection sites may occasionally itch.  Complications following Microsclerotherapy are very rare, but the solution can sometimes escape from the veins and cause inflammation in the skin surrounding the area. 

There is also a small risk of the development of tiny ulcers, which may leave a pink or white scar on healing. 

After treatment there may be persistent veins which are resistant to injections.  The treatment may cause brown discolouration (lasting up to 3 years) and, very rarely, the thread veins may be worse or new broken veins may appear.

However, numbness and brown discolouration may be permanent and the treatment may cause the appearance of more spider veins. In about 1-2% of cases, the treated areas may look worse permanently.

Occasionally vision may be temporarily disturbed for a few minutes or hours after Microsclerotherapy.  In addition, the treatment may cause migraines. 

As the years pass, more veins may develop.  All operations and procedures carry the risk of unsuccessful results, complications, injury or even death from both known and unforeseen causes. 

If you should experience significant complications it may require your care to be transferred to the National Health Service. 

Due to the prevalence of COVID-19 the Clinic has taken recommended steps to reduce the risk to both staff and patients, however there may be some residual risk remaining of contracting COVID-19 while at the clinic.

Leg Spider Veins can be treated safely and most people will get a good result that they are pleased with. The risks described can be avoided or reduced by suitably trained and experienced healthcare professionals working in a suitable clinical environment. 

I have leg spider veins on both legs. How much do you charge and can you treat all of them?

The fees for Leg Spider Veins are published on the website. You will see that the fee is “per session”. 

The area of leg spider veins that can be treated in a session is limited by the safe dose of sclerosant (the prescription medicine that is used to inject the spider veins) that can be administered “in one go”.  The dose of sclerosant that can be safely injected can treat roughly 2 or 3 patches of leg spider veins about the size of the outstretched hand. In practical terms this means that a patch corresponds to the outer thigh, the outer calf or the inner thigh. 

If both legs are affected and if there are large areas of spider veins, then it is important to prioritise what you want treated in a session. In practical terms, this means that the spider veins would be injected in the order in which they bother you most.

Each area of leg spider veins may require up to 3 treatments separated by an interval of at least 6-12 weeks.

What happens after Leg Spider Vein Treatment?

There are no particular do’s and dont’s. This is a walk-in, walk-out treatment.

After treatment by injection, the veins may look worse before they look better.  They may become lumpy and tender as part of the healing process, and this is helped by rubbing the area with an anti-inflammatory such as Ibuprofen gel.

About 10% of people develop a brown mark on the skin overlying the vein after sclerotherapy.  This discolouration mostly fades by 6 months but may take 2 to 3 years to disappear completely.  Serious side effects after sclerotherapy are extremely rare indeed.

After 3 treatments, the majority of people (approximately 90%) are pleased or very pleased with the results.  Approximately 5% are disappointed because they do not achieve the degree of fading desired.

Migraine sufferers may react to the injections with a migraine so we recommend you bring your usual migraine medication with you.  If you do not get a migraine after the first treatment, you are unlikely to suffer one at subsequent appointments

Will I have to wear stockings?

No. After Microsclerotherapy, medical compression stockings are not necessary. The only exception is if the spider veins are very big and there is some evidence that in this situation, compression promotes the healing process.