What causes varicose and thread veins on the legs?

Many people are distressed by the appearance of their legs – 15-20% of people have visible varicose veins, and an equivalent percentage may have hidden ones that can, nonetheless, cause symptoms such as aching legs, swollen ankles and discoloured patches of skin. Thread veins do not usually cause any medical symptoms, but are even more common; up to 84% of us have thread veins on one of our legs. Both conditions arise from the same basic issue: pressure in the vessels that return blood from the feet and legs back up to the heart.

“When you stand up, your heart has to pump blood against gravity,” says Professor Mark Whiteley, a consultant vascular surgeon. “Your veins contain valves to stop the blood falling back down the legs, but if they don’t close properly, the blood falls back down and stretches the vein wall, resulting in varicose veins.” The same pressure in the system can also cause smaller veins under the skin’s surface to become enlarged and therefore more visible, resulting in thread veins.

Is it all genetic, or are there things I can do to prevent them?

Although it is true that the more relatives you have with varicose veins, the more likely you are to develop them yourself, “it’s not as reliable as the inheritance of hair or eye colour,” says Bill Tennant, a consultant vascular surgeon, and senior examiner at the Royal College of Surgeons of Edinburgh. People who do a lot of standing do seem to be more prone to them, but they probably had a propensity to start with and standing aggravates the situation.

Pregnancy increases pressure on the leg veins, and can also increase the likelihood of some of the valves failing, while the pregnancy hormone, progesterone, can cause the walls of the veins to become more relaxed and stretchy. There is little evidence that taking hot baths or crossing your legs causes problematic leg veins, but thread veins can appear in response to trauma. “You often find them in horse-riders, on the inside of their knees, and you also sometimes get them where bra straps rub,” says Brian Newman, a consultant vascular surgeon who specialises in the removal of thread veins. They also become more prevalent with age.

Are they purely a cosmetic problem?

Thread veins are largely a cosmetic issue, but ignoring varicose veins can cause problems. For instance, an estimated 3-6% of people with varicose veins will develop leg ulcers – painful sores that can take months to heal – at some point. And a greater proportion of people may develop less serious symptoms, such as skin damage, or swollen ankles. The National Institute of Health and Care Excellence (Nice) recommends that anyone whose varicose veins are causing pain, aching, heaviness, ankle swelling – or problems such as bleeding, eczema or leg ulcers – should be referred to a specialist vascular service for a duplex ultrasound scan. This creates a picture of how blood is flowing through the legs and will identify any damaged valves. The problem is that some UK regions possess neither the funding, nor the specialist teams, to allow this. If your leg veins are not causing any medical symptoms, you could simply leave them alone, or you could pay for private treatment.

What treatments are available?

For varicose veins, Nice recommends endothermal ablation – in which the problematic veins are closed off using heat – or failing that, foam sclerotherapy, where a chemical foam is used to destroy the vein. Surgical “stripping” of varicose veins is third preference; it requires a longer hospital stay and more recovery time. For those whose varicose veins are causing symptoms, “compression hosiery should only be recommended as a permanent treatment, if the other options are unsuitable,” says Nice.

Thread veins can be treated at private clinics, where they may be injected with saline or another substance that causes the walls of the vein to collapse. Alternatively, they can be destroyed by heating them with microwaves delivered through a hair-width filament. This can be done during a lunch-hour, but treated areas can look as if a cat has scratched them for up to two months afterwards, and most people require three or four sessions. A new treatment being launched this month called Vein Away promises to focus heat even more precisely, resulting in a shorter recovery time and fewer treatments.

But surely we need our veins?

“A varicose vein by definition isn’t working properly, so losing it makes no difference,” says Tennant. There are a number of veins delivering blood back to the heart, so these will generally pick up the slack. If I get my veins treated, will more unsightly veins come back?

That depends on whether the root cause of the problem has been identified. “If you’ve got cracks in the wall, you need to make sure you check the foundations before you start painting again,” says Whiteley. The reason NICE advises people with varicose veins to be assessed with duplex ultrasound is to ensure that the defective vein is correctly identified; if it isn’t there’s a good chance your problems will return.

My varicose veins aren’t causing any symptoms. Is there anything else I can do to make them less visible?

You could try compression stockings. These provide gentle external support and encourage the blood in the veins to flow back towards the heart. “If you start wearing them as soon as you get early signs of varicose veins appearing, such as little spider veins around the ankles, it may stop them progressing to more severe symptoms,” says Rachael Sykes, a lymphedema specialist nurse and clinical support manager for Activa Healthcare, which manufactures compression stockings. However, “if someone has varicose veins and they stop wearing them, the problem will progress and they will come back again,” she says. Compression stockings can be bought over the counter, but Sykes recommends speaking to a GP to ensure you’re getting the right level of compression.

Are high-street beauticians adequately qualified to treat thread veins?

It is easy enough to get a certificate that allows you to treat thread veins, but, says Tennant, high-street beauticians “do not have the extensive training and regulation that medical practitioners have”. If a therapist misses the vein and injects into the surrounding tissue, this can result in brown patches, which can take several years to disappear. In rare cases, patients have also received burns from microwave treatment. “My advice is that if you’re going to get your veins done, find a reliable organisation and have a doctor do them,” Tennant says.