What Causes Spider Veins

Spider veins are a common concern, especially on the legs and face—whether due to discomfort or how they affect appearance. These thin red, blue, or purple lines sit just beneath the skin and often become more noticeable over time.

While they’re usually not dangerous, they can be bothersome, both cosmetically and physically. Some people notice itching, burning, or mild discomfort, while others simply wish their skin looked smoother and more even-toned.

But when it comes to understanding what actually causes spider veins, there’s a lot of confusion. Let’s clear up the myths and get to the root of the real causes—and the treatment options available if you’re ready to do something about them.

What Actually Causes Spider Veins

Spider veins develop when small blood vessels near the surface of the skin become enlarged or damaged. This happens when the valves inside the veins, which help regulate blood flow back to the heart, weaken over time.

When those valves don’t function properly, blood can pool and cause the veins to stretch and become more visible.

Genetics play a leading role. If your parents or close relatives have spider veins or other vein issues, you may be more likely to develop them yourself. This inherited tendency affects the strength and function of the vein walls and valves, making them more vulnerable to stretching over time.
Age also contributes, as vein walls lose elasticity with time. As circulation efficiency declines, superficial veins are more likely to swell and become noticeable under the skin, particularly in high-pressure areas like the legs and ankles.
Hormonal changes during life stages such as pregnancy and menopause—or with the use of birth control pills—can influence how veins function. Hormones like estrogen may cause vein walls to relax, which can make them more prone to developing spider veins. These changes are often temporary but may leave visible effects.
Prolonged sitting or standing, common in many professions, increases pressure in the lower legs. Gravity makes it harder for blood to return upward, and when circulation is restricted for long periods, the superficial veins in the legs can become congested and form visible spider veins.
Weight gain places additional pressure on leg veins, especially in the thighs, calves, and abdomen. Over time, this stress can cause veins to expand, especially if combined with other risk factors like a sedentary lifestyle or family history.
Sun exposure, particularly on the face, can weaken small blood vessels and accelerate their visibility. The thin skin around the nose and cheeks is especially vulnerable, which is why facial spider veins are often seen in people with fair skin or a history of frequent sun exposure.

Together, these factors contribute to a variety of visible vein patterns. Some people may notice spider veins developing gradually, while others may see a more sudden appearance due to life events like pregnancy or weight changes.

Common Misconceptions About the Causes Spider Veins

Despite how common spider veins are, there’s still a lot of confusion around what causes them and what they mean. Here are a few myths we hear regularly—and the facts that clarify them:

“Only older adults get spider veins.”
Spider veins do tend to become more common with age, but they can appear much earlier—sometimes even in your 20s or 30s. If you have a family history or lifestyle factors that impact circulation, you might see them earlier than expected.
“Crossing your legs causes spider veins.”
This one comes up often, but it’s a myth. Crossing your legs doesn’t create enough pressure to damage veins. What matters more is prolonged standing or sitting, especially without movement, which affects how blood flows in the legs over time.
“Spider veins are always a sign of a serious medical problem.”
Most of the time, spider veins are a cosmetic concern. However, if you also experience symptoms like swelling, aching, or heaviness in your legs, it’s a good idea to have them evaluated. A simple assessment can help rule out deeper vein issues and point you toward the right treatment, if needed.

How to Treat Spider Veins (Sclerotherapy)

The most effective and widely recommended treatment for spider veins is sclerotherapy. At Carolina Vein Care, this in-office procedure is performed by board-certified vein specialists using advanced mapping to ensure accuracy and optimal results.

Sclerotherapy involves injecting a safe, specialized solution directly into the affected veins. This solution causes the vein to close and eventually be reabsorbed by the body, improving both the appearance and comfort of the area over time. It’s a minimally invasive procedure that requires no anesthesia and no downtime—most patients return to their normal activities the same day.

At Carolina Vein Care, every treatment plan is customized using vein mapping to ensure comfort, precision, and efficiency. This ensures that each session is as effective as possible, with the fewest number of treatments needed.

After treatment, patients can expect gradual fading of the treated veins over a few weeks, with full results typically visible after several sessions. There may be minor bruising or tenderness, but these effects are temporary and easily managed. Preventive care and follow-up can help maintain results over the long term.

Spider Veins Are Treatable

If spider veins are affecting your comfort or confidence, expert care is available locally. With today’s minimally invasive treatments, addressing them can be simpler than you might expect. Understanding the real causes is the first step. And with today’s expert-led, minimally invasive treatments, addressing them is often simpler than expected.

Expert Care from Board-Certified Vein Specialists

Meet the Vein Experts:

Dr. Mark Jackson and Dr. Julie Park and board certified physicians and vein care experts.

At Carolina Vein Care, your care is led by two highly experienced physicians who specialize in the diagnosis and treatment of vein conditions.

Dr. Mark R. Jackson, MD is a board-certified vascular surgeon with over 30 years of experience. A former Lieutenant Colonel in the U.S. Army Medical Corps, he completed his fellowship at Walter Reed and went on to lead academic and clinical programs in vascular surgery. Dr. Jackson focuses on minimally invasive techniques that improve circulation and comfort with lasting results.

Dr. Julie U. Park, MD is a board-certified, fellowship-trained interventional radiologist. She trained at Northwestern University and brings two decades of experience in image-guided treatments for spider veins, facial veins, and aesthetic concerns. Known for her personalized approach, Dr. Park helps individuals feel confident and cared for through every step of their treatment.

Together, Dr. Jackson and Dr. Park provide physician-led care that combines expertise, modern techniques, and a thoughtful approach tailored to your needs.

Explore Spider Vein Treatment at Carolina Vein Care

If you’re in Simpsonville, Five Forks, or Greenville and exploring options to treat spider veins, our vascular specialists are here to guide you through your next steps.