Causes of Varicose Veins — Risk Factors and Prevention

Varicose veins affect approximately 23% of adults worldwide — yet many people don’t understand why they develop, or why treating them early matters. Understanding the root causes and risk factors helps you recognize when to seek evaluation and what to expect from modern minimally invasive treatment.

What Causes Varicose Veins?

The fundamental cause of varicose veins is chronic venous insufficiency — a failure of the one-way valves inside the leg veins. Healthy veins carry deoxygenated blood from the legs back to the heart against gravity, relying on these valves to prevent backflow. When the valves weaken or stop closing properly, blood pools in the veins and dilates them over time — producing the twisted, bulging vessels visible beneath the skin.

This backflow is called venous reflux and is the direct mechanism behind varicose veins, venous insufficiency, leg swelling, and venous ulcers. It is detected and measured by venous duplex ultrasound — the diagnostic standard performed at the initial consultation.

Risk Factors for Varicose Veins

Why Early Treatment Matters

Venous disease is progressive. Left untreated, mild varicose veins (CEAP C2) can advance to leg swelling (C3), skin changes including brown discoloration and eczema around the ankle (C4), healed venous ulcers (C5), and active open ulcers (C6) that are difficult to heal and significantly impair quality of life. Early treatment — before skin changes develop — is simpler, faster, and produces better long-term outcomes.

When to See a Vein Specialist

See a vein specialist if you experience: visible varicose veins causing discomfort; leg heaviness, aching, or swelling that worsens toward the end of the day; skin changes around the ankle; itching along veins; or a family history of varicose veins with worsening symptoms. A consultation with duplex ultrasound confirms whether venous reflux is present and which veins require treatment.

Treatment Options

All procedures are performed under local anesthesia. No general anesthesia, no hospital stay.

• VenaSeal (medical adhesive) — ₪15,000 — no compression stockings, return to work next day. May be covered by supplemental private insurance.
• EVLA (laser ablation) — at Shamir Medical Center via kupat holim tofes 17, at little or no direct cost to eligible patients.
• RFA (radiofrequency ablation) — at a private hospital through supplemental private insurance.
• Sclerotherapy — from ₪1,500 per session for spider veins; from ₪5,300 for venous insufficiency.

FAQ: Causes of Varicose Veins

What causes varicose veins in the legs?

The primary cause is failure of the one-way valves inside the veins, which allows blood to flow backward (venous reflux) and pool in the lower leg veins. Risk factors include heredity, prolonged standing, pregnancy, obesity, and age. The tendency to develop varicose veins is often inherited.

Are varicose veins hereditary?

Yes — genetics is the most significant risk factor. If one parent has varicose veins, the risk to their children is 40–50%. If both parents are affected, the risk rises to approximately 90%. However, lifestyle factors such as prolonged standing and obesity can accelerate the onset.

Does prolonged standing cause varicose veins?

Prolonged standing is a significant risk factor. Professions such as teachers, chefs, surgeons, and barbers are at elevated risk. Gravity increases venous pressure in the lower legs when standing, stressing the vein valves over time. Short walking breaks every hour can help reduce — though not eliminate — this risk.

Does pregnancy cause varicose veins?

Pregnancy is one of the most common triggers. Pregnancy hormones relax vein walls, and the growing uterus compresses the inferior vena cava, impeding venous return from the legs. Approximately 40% of pregnant women develop varicose veins during pregnancy. Some resolve after delivery, but many persist.

Does obesity cause varicose veins?

Obesity increases intra-abdominal pressure and venous pressure in the legs, accelerating valve damage. Weight loss can reduce symptoms and slow progression but will not resolve existing varicose veins — those require minimally invasive treatment.

When should I see a doctor for varicose veins?

See a vein specialist if varicose veins cause pain, heaviness, swelling, itching, or skin changes around the ankle. Seek urgent evaluation if you notice open wounds near the ankle, sudden redness and warmth along a vein, or rapid swelling of an entire leg. Early diagnosis allows simpler treatment and better outcomes.

Why are varicose veins painful?

Failed valves let blood pool in the vein, stretching its wall and raising the pressure in the surrounding tissue. The stretching and the low-grade inflammation it causes irritate nearby nerve endings. That is why the pain is typically an ache or heaviness that builds after standing and eases when the legs are elevated — and why closing the refluxing vein resolves it.

Genetics — the Most Significant Factor

Heredity is the single strongest predictor of varicose vein development. If one parent has varicose veins, the risk to their children is approximately 40–50%. If both parents are affected, the risk rises to ~90%. Genes influence valve structure, vein wall elasticity, and connective tissue strength — all of which affect how quickly veins become insufficient under pressure. Having a family history doesn’t mean varicose veins are inevitable, but it means earlier monitoring and lifestyle awareness are warranted.

Prolonged Standing — Occupational Risk

Professions that require standing for extended periods significantly increase venous pressure in the legs. Teachers, surgeons, chefs, nurses, construction workers, and barbers are among the highest-risk occupational groups. Without the pumping action of walking, blood pools in the lower leg veins, stressing the valve leaflets over thousands of working hours. Taking short walking breaks every hour and wearing compression stockings during shifts reduces — but does not eliminate — this risk.

Pregnancy

Pregnancy is one of the most common triggers of varicose veins in women. Two mechanisms operate simultaneously: pregnancy hormones (progesterone in particular) relax vein walls, reducing their tone and elasticity; and the growing uterus compresses the inferior vena cava, impeding venous return from the legs. Approximately 40% of pregnant women develop some degree of varicose veins during pregnancy. Some resolve after delivery; many persist or progress. Women who have had multiple pregnancies are at higher cumulative risk.

Obesity

Excess body weight increases intra-abdominal pressure, which in turn raises venous pressure in the legs. Abdominal obesity particularly compounds the effect by mechanically impeding venous return. Weight loss reduces symptoms and slows disease progression — but it does not reverse existing varicose veins. Those require minimally invasive treatment.

Age

Valve competence declines with age as elastin and collagen in vein walls degrade. Varicose veins are uncommon before age 20 and rise sharply in prevalence after 40. However, the process begins decades earlier — which is why risk factor management matters from midlife onward.

Prior Blood Clots or Vein Trauma

A history of deep vein thrombosis (DVT) can damage vein valves directly, leaving them permanently incompetent. Post-thrombotic syndrome — chronic venous insufficiency following DVT — is one of the more severe presentations of venous disease and requires specialist evaluation.