- What Causes Varicose Veins?
- Are Varicose Veins Dangerous If Not Treated?
- Common Symptoms of Varicose Veins
- Complications of Untreated Varicose Veins
- Warning Signs That Require Urgent or Emergency Care
- How Varicose Veins Are Evaluated
- Treatment Options for Varicose Veins
- Frequently Asked Questions
Although varicose veins are often looked at as a cosmetic concern by many individuals, they are a clinical sign of underlying vein disease. The veins themselves may not cause immediate harm for everyone, but the condition driving them – chronic venous insufficiency (CVI) – is progressive. Without evaluation and treatment, CVI tends to worsen over time and can lead to complications that are difficult, and in some cases impossible, to fully reverse.
What Causes Varicose Veins?
Varicose veins are enlarged, twisted veins that appear dark blue or purple beneath the skin, most commonly on the legs and feet. They form when the one-way valves inside the leg veins weaken or fail. Healthy valves keep blood moving upward toward the heart against gravity. When they malfunction, blood flows backward and pools in the vein — a process called venous reflux — causing the vessel to expand and bulge.
This valve failure is the defining feature of chronic venous insufficiency (CVI). CVI is a progressive condition: without treatment, venous pressure continues to build over time, tissue damage accumulates, and the risk of downstream complications increases. The visible varicose vein is often the outward sign of a process that has been developing for years.
Common contributing risk factors include:
- A family history of varicose veins or vein disease
- Age, particularly in adults over 50
- Prolonged standing or sitting, particularly in occupational settings
- One or more pregnancies
- Excess body weight
- A personal history of deep vein thrombosis (DVT) or prior leg injury
For a detailed look at how CVI advances through recognizable stages, see the stages of chronic venous insufficiency.
Are Varicose Veins Dangerous If Not Treated?
Varicose veins are a sign of underlying vein disease and should be evaluated by a medical professional. Whether they become dangerous depends largely on whether the underlying condition is addressed.
Vein disease is progressive. Even varicose veins that are currently painless may eventually produce symptoms — leg swelling, cramping, heaviness, and fatigue — as venous pressure continues to build. Over time, that pressure damages surrounding tissue, creates conditions that favor clot formation, and can lead to skin changes that are very difficult to reverse.
Most people with varicose veins will not develop a life-threatening complication. However, the risk is real and rises with three key factors: how advanced the vein disease is, how long it has been present without treatment, and whether additional contributing conditions are present. Early evaluation is the most effective way to understand your individual risk and address the condition before it progresses.
For a closer look at how the condition progresses without treatment, see what happens if varicose veins are left untreated.
Common Symptoms of Varicose Veins
Varicose veins do not always cause symptoms. Some people notice the visible veins but feel no discomfort. Others experience a range of symptoms that worsen over time as the underlying vein disease advances. Common symptoms include:
- An achy, heavy, or tired feeling in the legs — often worse at the end of the day
- Throbbing, burning, or cramping in the legs, particularly in the calves
- Swelling in the lower legs and ankles
- Itching around the affected vein
- Pain that worsens after sitting or standing for extended periods
- Skin discoloration or texture changes near the ankle
- Restless legs, especially at night
Symptoms that involve skin changes near the ankle — including discoloration, thickening, or any sore that is not healing — are particularly important to have evaluated promptly. These changes indicate that CVI has progressed beyond the veins themselves and begun to affect surrounding tissue.
Complications of Untreated Varicose Veins
The following complications are not inevitable for everyone with varicose veins. They represent what the clinical evidence shows can develop when chronic venous insufficiency advances without evaluation or treatment.
Bleeding
Because varicose veins sit close to the skin’s surface under elevated pressure, they are vulnerable to rupture. Minor contact — bumping a leg against furniture, shaving, or light scratching — can cause a vein to burst and bleed. The bleeding is often heavier than the injury warrants and can be difficult to control without sustained direct pressure and leg elevation.
A systematic review of hemorrhage from varicose veins published in the International Wound Journal confirmed that spontaneous or traumatic bleeding from surface varicosities can, in rare cases, result in serious blood loss.1 Bleeding from a varicose vein is a clear sign that evaluation should be prioritized.
Deep Vein Thrombosis (DVT) and Pulmonary Embolism
Varicose veins affect the superficial venous system; deep vein thrombosis (DVT) forms in the larger veins deeper within the leg. The two systems are connected, and conditions that allow blood to pool and slow — including advanced CVI — create an environment where clot risk increases.
A large retrospective cohort study published in JAMA analyzed over 425,000 propensity-matched adults and found that individuals with varicose veins had a hazard ratio of 5.3 for developing DVT compared to matched controls over a median follow-up of 7.5 years.2 The risk was highest during the first year after diagnosis. The researchers note that varicose vein patients show elevated levels of inflammatory and prothrombotic markers, which may contribute to this elevated risk. The study was observational and the authors acknowledge that unmeasured factors — including obesity and smoking — may account for part of the association. Most people with varicose veins will not develop DVT. The risk rises when vein disease is advanced or combined with additional factors.
If a DVT clot breaks free and travels to the lungs, the result is a pulmonary embolism — a medical emergency. Warning signs and the appropriate response are covered in the section below.
For a detailed look at how this connection works, see how untreated varicose veins can raise DVT risk and varicose veins and blood clots: warning signs.
Venous Leg Ulcers
Venous leg ulcers are among the most serious and difficult-to-manage consequences of advanced CVI. Research consistently shows that venous disease accounts for 60–80% of all leg ulcerations.3 These open wounds typically develop near the ankle, where venous hypertension and tissue damage are most pronounced.
A national registry study from the American Vein & Lymphatic Society reviewed more than 270,000 patient records and found that 85% of leg wounds presenting to vein centers were venous in origin — and 97% of those patients had correctable superficial venous insufficiency.4 This means the underlying cause was treatable in nearly every case.
Venous ulcers heal slowly. Research estimates only about 40% of venous leg ulcers heal within three months, and up to 80% recur within three months of healing if the underlying vein disease is not treated.3 They are painful, prone to infection, and represent the most advanced stage of untreated vein disease.
Lipodermatosclerosis
Lipodermatosclerosis is an inflammatory condition of the subcutaneous fat in the lower leg that develops in the setting of chronic venous hypertension. People who have the condition typically notice swelling above the ankle initially. In its early stage, it can appear similar to cellulitis, with redness, swelling, and localized pain.
As the condition progresses, the skin hardens, thickens, and becomes discolored. The lower leg may develop a tapered appearance above the ankle. Increased pigmentation and small white scars may also appear in the affected area. Once established, lipodermatosclerosis does not fully reverse even after vein treatment — though treating the underlying disease can reduce ongoing inflammation and slow further progression.
Women develop lipodermatosclerosis more commonly than men. It is most prevalent in patients with long-standing chronic venous insufficiency or varicose veins. A case-control study found that the presence of lipodermatosclerosis in varicose vein patients was independently associated with an odds ratio of 8.9 for developing a venous ulcer.5 Symptoms should be evaluated by a vein specialist as soon as possible.
Skin Changes and Venous Stasis Dermatitis
As venous pressure increases over time, fluid and iron-laden red blood cells can leak into the tissue surrounding the veins. This produces brownish or reddish discoloration near the ankles — called hemosiderin staining — along with a rash-like condition known as venous stasis dermatitis, persistent itching, and skin that becomes dry, scaly, or fragile.
These changes are often underestimated. Clinically, they signal that CVI has progressed beyond the vein walls and begun to damage surrounding skin and soft tissue. They are also a recognized predictor of venous ulcer risk and should not be managed as a surface skin condition without investigating the underlying venous disease.
Warning Signs That Require Urgent or Emergency Care
Some varicose vein symptoms call for a scheduled evaluation. Others require same-day care or an emergency room visit. Knowing the difference is important.
DVT Symptoms: Seek Same-Day Evaluation
DVT symptoms differ from routine varicose vein discomfort in important ways. They tend to appear suddenly, affect one leg, and worsen rather than improve with rest or elevation. Seek medical evaluation the same day — not at a future appointment — if you experience:
- Sudden swelling in one leg that develops within hours
- Deep, aching pain in the calf or thigh that feels internal rather than surface-level
- Skin that becomes red, warm, or tender in a localized area without an obvious cause
- A leg that feels noticeably heavier or tighter than the other
- Symptoms that come on quickly and continue to worsen
A physical examination cannot rule out DVT. Duplex ultrasound imaging is required to confirm or exclude a clot. Do not wait to see if these symptoms resolve on their own.
Pulmonary Embolism: Call 911
If a DVT clot dislodges and travels to the lungs, a pulmonary embolism can develop rapidly. This is a life-threatening emergency. Call 911 or go to the nearest emergency room immediately if you experience:
- Sudden shortness of breath with no clear explanation
- Chest pain that worsens when breathing in deeply
- A racing or irregular heartbeat
- Coughing up blood
- Lightheadedness, dizziness, or fainting
Do not drive yourself. Do not wait to see if symptoms improve. Pulmonary embolism requires emergency care that is outside the scope of outpatient vein treatment.
If you recognize any of these warning signs, a vein specialist can evaluate your condition with a duplex ultrasound at a convenient outpatient location near you.
How Varicose Veins Are Evaluated
The best way to understand whether your varicose veins are problematic is a consultation with a vein specialist. Evaluation typically begins with a physical examination, but it is confirmed with a duplex ultrasound — a non-invasive imaging test that uses sound waves to visualize blood flow through both the superficial and deep venous systems in real time.
Duplex ultrasound can identify valve failure, venous reflux, blood pooling, and whether CVI is present — even when veins are not visibly prominent on the surface. It can also determine whether a clot is present and where it is located. A physical examination alone is not sufficient to assess the extent of vein disease or exclude DVT.
Prior to your appointment, it can be helpful to note any changes in the skin near your varicose veins — including color changes, areas of redness or thickening, or any sore that is not healing. These observations help a vein specialist prioritize what to look for during the ultrasound evaluation.
Not sure if your symptoms warrant a visit? See when to worry about varicose veins and how to know when varicose veins need treatment.
Treatment Options for Varicose Veins
When evaluation confirms underlying vein disease and treatment is appropriate, several minimally invasive, outpatient options are available. These vein treatments close or seal the affected vein, redirecting blood through healthier pathways. Most take less than an hour, require no general anesthesia, and allow patients to return to normal activity the same day.
Treatment options may include:
- Endovenous laser therapy (EVLT): Laser energy delivered through a thin catheter closes the diseased vein from within
- Radiofrequency ablation (RFA): Controlled radiofrequency energy heats and seals the vein wall without an incision
- VenaSeal™: A medical adhesive that closes the affected vein without heat or sclerosant
- Varithena: A microfoam solution injected to collapse the vein and redirect blood flow
- ClariVein®: Combines mechanical disruption with a sclerosing agent for winding or complex veins
- Ultrasound-guided sclerotherapy: A sclerosing solution injected under imaging guidance to close smaller varicosities
When CVI is the underlying cause, treatment is often covered by insurance when medical necessity has been established. USA Vein Clinics verifies insurance coverage at the time of scheduling. Appointments are available at over 160 accredited outpatient locations nationwide.
SCHEDULE YOUR CONSULTATION ONLINE
Frequently Asked Questions
Are varicose veins always dangerous?
Not automatically. Most people with varicose veins will not develop a serious complication. However, varicose veins are a sign of chronic venous insufficiency — a progressive condition — and the risk of complications including blood clots, venous ulcers, and irreversible skin changes rises the longer it goes without evaluation and treatment.
Can varicose veins cause blood clots?
Research shows an association. A 2018 JAMA study of over 425,000 adults found a 5.3-fold higher rate of DVT in people with varicose veins over a 7.5-year follow-up period.2 Risk rises when vein disease is advanced or combined with other factors such as prolonged immobility, obesity, or a personal history of clotting. For a full breakdown, see can varicose veins turn into DVT.
What should I do if a varicose vein bleeds?
Apply firm, direct pressure to the area and elevate the leg above heart level. Most bleeding can be controlled this way. If bleeding is heavy, does not stop within a few minutes, or recurs, seek medical attention promptly. Bleeding from a varicose vein is a sign that vein evaluation should not be delayed.
What skin changes near the ankle should concern me?
Brownish or reddish discoloration, itchy or scaly patches, skin that feels hard or thickened above the ankle, and any wound near the ankle that is not healing within two weeks are all signs that CVI may be advancing. These changes are associated with an elevated risk of venous ulcers and should be evaluated with duplex ultrasound rather than treated as a surface skin condition.
What is the difference between a superficial clot and DVT?
A superficial clot forms in the veins close to the skin’s surface, often within or near a varicose vein. It typically causes localized redness, warmth, and a firm, cord-like feeling along the vein. DVT forms in the deeper veins within the leg and carries a higher risk because the clot can travel to the lungs and cause a pulmonary embolism. Duplex ultrasound is required to distinguish between the two — symptoms can overlap significantly.
How do I know if my varicose veins need treatment?
Leg pain, swelling, heaviness, skin changes near the ankle, or a non-healing wound are all symptoms that suggest treatment may be appropriate. A duplex ultrasound with a vein specialist is the most accurate way to assess whether CVI is present and whether treatment is recommended. See how to know when varicose veins need treatment for a full breakdown.
Does treating varicose veins reduce the risk of complications?
Treating underlying vein disease addresses the conditions that allow complications to develop — including venous stasis, chronic inflammation, and elevated venous pressure. The national registry data referenced above found that 97% of patients presenting with venous leg ulcers had correctable superficial venous insufficiency, suggesting that earlier treatment may prevent advanced complications in many cases.4
Does insurance cover varicose vein treatment?
When treatment is medically necessary due to symptoms of CVI, it is often covered by insurance. USA Vein Clinics accepts most major insurance plans and completes insurance verification at the time of scheduling.
SCHEDULE YOUR CONSULTATION ONLINE
Citations:
- Serra R, Ielapi N, Bevacqua E, et al. Haemorrhage from varicose veins and varicose ulceration: a systematic review. Int Wound J. 2018;15(5):829-833.
- Chang SL, Huang YL, Lee MC, et al. Association of varicose veins with incident venous thromboembolism and peripheral artery disease. JAMA. 2018;319(8):807-817.
- Probst S, Weller CD, Bobbink P, et al. Prevalence and incidence of venous leg ulcers: a systematic review and meta-analysis. Int Wound J. 2023;20(8):2439-2452.
- Lakhanpal S, Lakhanpal G, Deol ZK, Franzon G. Venous leg ulcers and prevalence of surgically correctable reflux disease in a national registry. J Vasc Surg Venous Lymphat Disord. 2023;11(2):283-290.
- Barwell JR, Davies CE, Deacon J, et al. Risk factors for chronic ulceration in patients with varicose veins: a case control study. J Vasc Surg. 2009;49(6):1242-1247.
- Antani MR, Dattilo JB. Varicose Veins. In: StatPearls. National Institutes of Health. Updated August 8, 2023.
