Vein Treatment Clinic logo
Consulta tu seguro médico

What Causes Varicose Veins?

Badge Check Blue

Medically verified

Last updated on 1/29/2026

Badge Check Blue

By Dr. Michael Nguyen

Vein Doctor at Vein Treatment Clinic

Harvard Medical School

Board Certified by the American Board of Venous and Lymphatic Medicine

Estas venas várices develop when the veins in the legs cannot move blood efficiently back toward the heart. Increased pressure builds inside the vein, causing it to enlarge, twist, and become visible beneath the skin.

When patients ask what causes varicose veins in the legs, the answer usually involves a combination of valve failure, genetics, aging, pregnancy, and prolonged standing. Understanding the causes of varicose veins and their risk factors helps explain why they form and why some people are more likely to develop them.

YouTube #!trpst#trp-gettext data-trpgettextoriginal=7#!trpen#video#!trpst#/trp-gettext#!trpen#

Understanding why varicosas forms helps patients recognize risk factors, anticipate progression, and decide when evaluation or treatment may be helpful.

If you’re unsure which factors may be contributing to your veins, a vein evaluation can help clarify the cause.

Valve failure inside the veins

The most common cause of varicose veins is failure of the one way valves inside the leg veins. These valves normally keep blood moving upward toward the heart, which may raise the question. Are they dangerous? These valves normally keep blood moving upward toward the heart.

When valves weaken or stop closing properly, blood flows backward and pools in the vein, increasing pressure and stretching the vein walls. This valve dysfunction is the primary reason varicose veins form.

Medical illustration comparing a healthy vein with open and closed valves versus an unhealthy vein with a broken valve leading to blood pooling

Healthy vs. damaged vein valves.

Medical illustration comparing a healthy vein with open and closed valves versus an unhealthy vein with a broken valve leading to blood pooling

Healthy vs. damaged vein valves

Genetics and family history

Genetics play a major role in why varicose veins form especially in families with inherited valve weakness. People with close family members who have varicose veins are more likely to develop them.

Inherited vein wall weakness or valve structure increases susceptibility, even in otherwise healthy individuals.

Does vein disease run in your family? Check Your Insurance Coverage

Why varicose veins are more common with age

Aging and varicose veins are closely linked. As people age, vein walls lose elasticity and valve function can decline.

These age related changes increase the likelihood of blood pooling and visible vein enlargement over time.

Pregnancy and hormonal changes

Pregnancy and varicose veins are commonly associated due to increased blood volume, hormonal changes, and added pressure on the leg veins.

Hormones relax vein walls, making valve failure more likely. While some veins improve after pregnancy, underlying valve damage can persist.

Temporary Change or Lasting Issue? Learn How Pregnancy Affects Your Vein Health

Symptom Checker

Unsure if you need treatment? Select your symptoms below:

Prolonged standing or sitting

Prolonged standing causes varicose veins to worsen by reducing the muscle pumping action that helps move blood upward.

Over time, standing for long periods increases vein pressure and accelerates valve dysfunction, especially in individuals with existing risk factors.

Excess weight and increased vein pressure

Additional body weight increases pressure on the veins in the legs, making it harder for blood to return to the heart.

While weight alone does not cause varicose veins, it can worsen existing vein disease.

Worried about weight-related vein pain? Consult an Expert Today

Five star icons

Get treated by vein treatment industry leaders

Results that speak for themselves

You can expect results like these with our specialized treatments for spider & varicose veins performed by the best experts in the country.

Before

BA_11_20_40_VV before

After

BA_11_20_40_VV after
Click to view patient story Tap to view patient story

A 37-year-old patient visited our Vein Treatment Clinic, seeking relief from unsightly and painful varicose and spider veins. We performed radiofrequency ablation and sclerotherapy treatments, significantly improving the veins’ appearance and completely eliminating discomfort. The patient is now enjoying a more active and pain-free lifestyle.

Before

BA10_61+_SV before

After

BA10_61+_SV after
Click to view patient story Tap to view patient story

A 69 year-old patient visited our California Vein Clinic, embarrassed by spider veins that had impacted their self-esteem. We performed radiofrequency ablation and sclerotherapy treatments, leaving their legs smooth and healthy. The patient now feels more confident, thanks to this transformative treatment.

Before

BA9_61+_SV before

After

BA9_61+_SV after
Click to view patient story Tap to view patient story

This 84 year-old patient at our New Jersey Vein Treatment Clinic came in with spider veins that had affected their daily routine. We used radiofrequency ablation and sclerotherapy treatments to relieve discomfort and restore both their leg health and confidence. The patient now enjoys a more active and fulfilling lifestyle, free from pain.

Before

BA8_61+_SV before

After

BA8_61+_SV after
Click to view patient story Tap to view patient story

At our Long Island Vein Clinic, we treated this 75 year-old patient with spider veins using radiofrequency ablation and sclerotherapy. These minimally invasive treatments improved both the patient’s appearance and overall well-being, offering transformative results.

Before

BA7_61+_SV before

After

BA7_61+_SV after
Click to view patient story Tap to view patient story

This 75 year-old patient visited our Long Island Vein Treatment Clinic with painful spider veins. We used radiofrequency ablation and sclerotherapy, minimally invasive treatments, to eliminate the veins and restore comfort and confidence. The patient experienced life-changing results

Previous blood clots or vein injury

A history of blood clots or injury to the veins can damage valves and disrupt normal blood flow.

This damage increases the risk of developing varicose veins later on.

Do lifestyle factors cause varicose veins?

Lifestyle factors such as inactivity, prolonged immobility, and excess weight contribute to increased vein pressure and symptom progression.

While these factors influence how varicose veins develop, they typically act in combination with underlying valve weakness rather than serving as the sole cause.

Lifestyle changes may reduce symptoms but do not reverse valve damage once it has occurred.

Not sure which of these causes applies to your situation? Talk With a Vein Specialist

Most PPO insurances cover vein treatment!

and 100+ more

Speak with an expert at 844-690-1788

< Spider veins vs Varicose veins

What Are the Symptoms of Varicose Veins? >

About the Medical Team at Vein Treatment Clinic

Vein Treatment Clinic is powered by VIP Medical Group and built around a single guiding principle: deliver the highest standard of vein care using an academic, evidence-based approach combined with the most advanced, minimally invasive technology available today.

Clinical leadership at Vein Treatment Clinic is guided by a panel of board-certified vein specialists responsible for establishing and maintaining the clinic’s medical standards. Their approach reflects training and experience developed at nationally recognized academic institutions such as Harvard, Yale, Columbia, and Mount Sinai, with a focus on disciplined evaluation, accuracy, and outcomes-driven care.

All physicians at Vein Treatment Clinic follow a structured, highly standardized clinical model. This includes ongoing training in the latest non-surgical vein treatments, continuous review of emerging research, and strict adherence to proven safety and quality protocols. The approach reflects the values of academic medicine: thoughtful evaluation, disciplined decision-making, and a commitment to outcomes grounded in science.

Group of Vein Treatment Clinic Badges
YouTube #!trpst#trp-gettext data-trpgettextoriginal=7#!trpen#video#!trpst#/trp-gettext#!trpen#

See how we change lives

Start Your Journey to Pain-Free Legs

Patients benefit from a team-based model of care where expertise is shared, best practices are consistently applied, and treatment recommendations are driven by data, experience, and long-term results. This ensures that every patient receives the same high level of care, regardless of which physician they see.

At Vein Treatment Clinic, education is considered a core part of treatment. Patients are encouraged to understand their condition, their options, and the reasoning behind each recommendation, so they can move forward with clarity and confidence.

If you’d like clarity about what may be causing your varicose veins and what next steps make sense, a vein evaluation can help guide that decision.

We’ll verify
your insurance
coverage for you

Please fill out the form provided, and one of our dedicated patient coordinators will promptly reach out to you.

During the call, they will assist you in scheduling your visit at a convenient time and will also verify your insurance coverage to ensure a smooth and stress-free experience.

We are here to help guide you through every step of the process!

Your information is encrypted and secure. By submitting this form, you agree to our Communications Terms y Política de Privacidad. and consent to receive SMS and email communications. You may opt out at any time. We are HIPAA-compliant and value your privacy.

Veintreatmentclinic Medical Center Icon
Instagram-icon

veintreatmentclinic

Medical Center

What Causes Varicose Veins? | Risk Factors & ReasonsJuan Jose Madrigal