Spider veins (also called telangiectasia or venulectasias) are enlarged veins near the skin surface that appear purple, red, or blue. They are commonly found on the legs, though they can also appear on the face and other parts of the body.

These enlarged veins are usually short unconnected lines or arranged in a sunburst pattern like a spider’s web. Unsightly spider veins can occur in small, unnoticed areas, but they can also grow to cover a large area of skin if left untreated.

Most spider veins don’t hurt – they don’t have any symptoms beside looking bad. That’s why they are usually only considered as a cosmetic problem. In rare cases, spider veins that develop from deeper “reticular” or feeder veins may come with a burning sensation, itching, or dull throbbing pain. 

Typically, spider veins appear to have diameters of 1 mm or less, but their actual diameters may up to 3 mm under the surface. Small spider veins are usually pinkish red, whereas larger spider veins are blue or purple in color.

Sometimes, a cluster of spider veins may appear as a red or purple patch called blushing or matting (telangiectatic matting) that are often mistaken for bruises. Unlike bruises, however, spider vein mattings do not fade with time. 

Another form of spider veins, called an ankle flare, is a cluster of spider veins – usually associated with another form of vein problem called varicose veins – that is located on the inner ankle.

Spider veins affect mostly women, though it can also occur in men.

To understand the root cause of spider veins, we have to step back a little and talk about veins.

Veins are a big part of your body’s circulatory system – they carry blood back to the heart after it has delivered nutrients to the body’s tissues. Inside these veins are a series of one-way valves that ensure that the blood travels only toward the heart. These valves separate veins into many internal segments.

When the valves don’t work properly, blood can “build up” in a segment of the vein. This increases the pressure on the vein and causes the vein walls to stretch. After a while, the stretched vein walls would develop micro-tears and leaks that allow blood and metabolism by-products to seep out and stain the outside of the veins. We see this as the unsightly purple, red, and blue color of spider veins.

Left untreated, the stretched vein walls in one segment of the vein will lead to valve failures in neighboring segments – just like a domino effect. That’s why when they are left untreated, small spider veins will “grow” into large ones.

There are several factors that cause some people, but not others, to develop spider veins:

Genetics
Most women with spider veins have mothers and/or grandmothers who also have them. These women unfortunately inherit a tendency for weak vein walls and poorly functioning vein valves.

They also tend to develop spider veins at a relatively young age (in their thirties or even in their twenties). Their spider vein conditions also tend to be more severe, like multiple patches that grow larger year after year.

Hormones
During pregnancy, and to a lesser degree also during their monthly cycles, fluctuations in the female sex hormone estrogen and progesterone cause the softening of the vein walls and valves. This makes a woman’s veins more prone to stretching.

Increased blood volume, which is needed to provide circulation to the fetus, also causes increased pressure on the vein walls. The growing fetus also exerts pressure on the pelvis, which in turn, causes more pressure on the leg veins.

Some women see spider veins develop during their pregnancies that persist after their babies are born. Others see these veins disappear after the birth of their babies, only to see them reappear later in life.

Prolonged standing or sitting
Both prolonged standing and sitting cause a great amount of pressure to develop in leg veins. In both conditions, the calf muscles are inactive and therefore cannot help push venous blood to return to the heart. This causes blood to pool in the veins, thus resulting in increased pressure on the vein walls.

This pressure drops once you begin to walk, so if your job requires you to stand or sit for prolonged periods, remember to take short breaks and walk around for a few minutes every hour.

Injury or trauma
In some people, spider veins appear after injury or trauma to the vein. These include broken ankle, surgery, car accident or sports injury. Bruising, which is pooled blood resulting from broken veins under the skin, can also lead to an inflammatory response, which in turn, can result in enlarged veins.

Sometimes, spider veins can appear many years after the wound has healed (for instance, if you bruised your shin by accidentally banging it against the coffee table, spider veins can appear in that location years afterwards.)

Vein conditions
In men, spider veins are usually the result of blow-outs from nearby varicose veins. High pressure from these veins cause neighboring smaller veins to stretch and enlarge. These spider veins are usually darker and have larger diameters than the spider veins in women.

Spider vein matting, which resemble bruisings that do not fade, is often caused by the healing process of injuries and bruises, as well as complications from schlerotherapy.

Ankle flares, or cluster of spider veins found on the inside of ankles, are often associated with chronic venous insufficiency (CVI), a form of poor circulation where venous blood is not efficiently returned to the heart.

For most people, spider veins occur in their legs. But there are instances where fine veins in the face and nose area become enlarged and darker in color.

For some, prominent facial veins are caused by rosacea. This condition is marked by numerous red spider veins in the nose, cheek, forehead, and chin, and is sometimes accompanied by acne breakouts. Although the cause of rosacea is not known, it seems that alcohol, spicy food, and stress may play a role.

Chronic sun exposure can also cause or exacerbate facial spider veins. In some people with chronic allergies, repetitive coughing and sneezing can lead to enlargement of veins around the nose and below the nostrils. Bouts of violent vomitings can also lead to spider veins on the cheeks.

The first three factors account for most of the causes of spider veins. Please keep in mind that there may be a primary and several secondary or contributing factors to spider veins, and that these factors may not contribute equally to spider veins in different individuals.

A laser is basically a concentrated beam of light that when focused on a particular spot, can create a large amount of destructive heat. When applied to the skin, the laser’s thermal energy is absorbed primarily by blood cells inside the spider vein. These blood cells become very hot and create a clotting effect which collapses or closes the vein. The body will then slowly remove the collapsed veins, and thus reduce the appearance of the spider veins.

Depending on the machine used, there are various forms of laser treatments. These include argon laser, pulsed dye laser, and intense pulsed light. 

Laser theraphy can also be adapted to treat pigmented lesions and warts, as well as to remove unwanted hair. Because it is less painful than sclerotheraphy, laser is often the preferred treatment method for fine spider veins, especially the ones in the face. However, even this treatment has several drawbacks:

*First and foremost, the effect of laser is often temporary because it does not address the root cause of the vein conditions – most people see their spider veins come back after the procedure. The result is also variable – some people experience very good results, whereas others see virtually no changes.

Laser therapy is often very expensive and is not covered by most insurance policies. A patient may also need several rounds of laser therapy to see the effects.

Laser is less effective for spider veins in the leg and for larger spider veins.

In people with darker skin, laser is usually not as effective as in people with lighter skin. This is because the skin pigment melanin also absorbs the laser’s energy, thus diverting the laser’s effect on spider veins.

Although laser therapies are less painful than sclerotherapy, it is not completely painless. Some feel stinging or burning sensation, which may last for several hours. Others may experience blisters and skin discoloration in the treated area.