Deep Vein Thrombosis vs Varicose Veins

Deep vein thrombosis (DVT) and varicose veins are two vein-related conditions that are often mistaken for one another. However, while both conditions involve the veins and can cause leg discomfort, they differ significantly in terms of severity, causes, symptoms, and required treatment. For example, untreated DVT can lead to a life-threatening pulmonary embolism, while untreated varicose veins may cause chronic pain and skin ulcers.

If you or a loved one is experiencing leg pain, swelling, or notices visible varicose veins, don’t wait. At CACVI, our team of board-certified vascular specialists brings over 30 years of experience in diagnosing and treating vein conditions. We’re here to provide clear answers, personalized care, and lasting relief. Contact us today to schedule your consultation

This post will focus on clearly explaining the differences between DVT and varicose veins. It will help you recognize the warning signs of each, understand their potential complications, and know when to seek medical attention.

What Are Varicose Veins?

Varicose veins are swollen, twisted, and enlarged veins that typically appear in the legs and lower limbs. They develop due to valve dysfunction within the veins, when these small one-way valves become weak or damaged, blood flow is disrupted and begins to move backward instead of toward the heart. This leads to blood pooling in the veins, which increases pressure and causes the veins to become visibly bulging, twisted, and often blue or purple in color. 

These affected veins are usually found near the skin’s surface, also known as superficial veins. Although they may start as a minor cosmetic issue, untreated varicose veins can signal underlying vascular conditions and progress to more serious health concerns.

The symptoms of varicose veins can vary but often include visible, bulging veins that appear twisted and discolored. Many people experience leg swelling, a heavy or aching feeling in the legs, itching around the veins, and in some cases, muscle cramps. These symptoms tend to worsen after extended periods of standing or sitting and can lead to ongoing discomfort in the affected leg. Over time, they may begin to interfere with daily activities and overall quality of life.

Several factors can contribute to the development of varicose veins. The most common causes include aging, pregnancy, prolonged standing, and obesity, all of which place extra pressure on the vein valves and can weaken them over time. Individuals who stand or sit for long periods of time, especially those in occupations like nursing, teaching, retail, or office work, are also at increased risk.

While varicose veins are more commonly associated with women, men can also get varicose veins, particularly if they have a family history, are overweight, or live a sedentary lifestyle. Other risk factors include high blood pressure, a history of blood clots, certain medical conditions, and even heart failure, which all contribute to abnormal blood pressure in the lower legs and poor blood flow through the veins.

What Happens If Varicose Veins Are Left Untreated?

When left untreated, there could be a range of serious complications associated with varicose veins. One of the most common issues is chronic pain or persistent discomfort in the legs, including knee pain in some individuals. Additionally, untreated varicose veins can lead to skin ulcers, particularly around the ankles, due to long-term pressure and impaired blood circulation. These ulcers are slow to heal and are prone to infection.

Another potential complication is spontaneous bleeding, as fragile, swollen veins close to the skin can rupture easily. Over time, patients may also develop venous eczema, a skin condition marked by inflammation, itching, and irritation near the veins. Furthermore, skin discoloration appears, often a reddish or brownish stain, around the affected veins, signaling long-term damage and inflammation.

What Is Deep Vein Thrombosis (DVT)?

Deep vein thrombosis (DVT) is a serious vascular condition that occurs when a blood clot forms in one of the body’s deep veins, most commonly in the lower legs or thighs. Unlike superficial vein conditions like varicose veins, DVT affects the deeper blood vessels, where clots are more likely to lead to complications. This type of vein thrombosis can partially or completely block blood flow, posing a major threat to health if not treated promptly. If a blood clot breaks free, it may travel through the bloodstream to the lungs and cause a pulmonary embolism, a life-threatening emergency. 

There are several causes behind developing deep vein thrombosis, but one of the most common is prolonged immobility. Situations like bed rest, long flights, or recovery after recent surgery can reduce blood circulation and increase the chances of a blood clot forming in the deep veins. 

Various risk factors increase the likelihood of DVT. These include age, especially over 60, genetics and family history, obesity, pregnancy, smoking, and the use of hormonal medications such as birth control. Individuals with high blood pressure or medical conditions that affect blood flow are also at a higher risk. The National Blood Clot Alliance emphasizes awareness of these risk factors and recommends regular exercise, avoiding sitting for long periods, and wearing compression stockings when needed to help prevent vein thrombosis.

DVT symptoms may begin subtly, but early detection is key. The most common signs include swelling in one leg, pain or tenderness in the affected limb, and warmth or redness of the skin over the affected veins. The skin may appear discolored, and there can be a heavy feeling in the affected area. In some cases, people may confuse these signs with those of varicose veins. However, DVT is a much more serious condition that requires immediate medical care.

If the blood clot travels to the lungs, it can trigger a pulmonary embolism (PE), with symptoms like sudden shortness of breath, chest pain, dizziness, or even coughing up blood. This represents a true medical emergency. Seeking professional medical advice at the first sign of symptoms is critical to preventing severe complications.

What Happens if DVT Is Left Untreated?

Without timely medical attention, deep vein thrombosis can cause devastating long-term effects. The most dangerous outcome is a pulmonary embolism, where the blood clot breaks free and becomes lodged in the lungs, cutting off oxygen and potentially leading to death if untreated. Another long-term complication is post-thrombotic syndrome, which results in chronic pain, swelling, and skin changes in the affected leg.

DVT may also lead to chronic venous insufficiency (CVI), where damaged vein valves prevent proper blood flow, causing ulcers, skin discoloration, and leg fatigue. In extreme cases, tissue damage due to restricted circulation can lead to gangrene, a rare but life-altering complication where surgical removal of tissue may be required. People who have experienced DVT are at an increased risk of recurrence of clots, which may affect the same or other veins.

Deep Vein Thrombosis vs. Varicose Veins: Key Differences

If you’re noticing changes in your legs like swelling, discoloration, or bulging veins, it’s important to understand whether you’re dealing with varicose veins or something more serious like deep vein thrombosis (DVT). While both conditions affect the veins, they show up very differently and carry different levels of risk.

Varicose veins are usually easy to spot. They appear as enlarged, twisted, or bulging veins near the surface of the skin, often blue or purple in color. These veins are typically painless but may cause aching, heaviness, or itching in the legs, especially after long periods of standing.

DVT, by contrast, often has no visible signs on the skin. When symptoms do occur, they may include swelling (usually in one leg), warmth, redness, and a deep, cramping pain in the calf or thigh. However, these signs can be subtle and are not always obvious to the naked eye, which makes DVT especially dangerous if left untreated.

Because DVT involves a blood clot in the deeper veins, it cannot be confirmed just by looking at your leg. If DVT is suspected, a venous ultrasound or other imaging test is needed for an accurate diagnosis.

Can Varicose Veins Cause Deep Vein Thrombosis?

While varicose veins themselves are typically found in superficial veins, they may contribute to developing deep vein thrombosis due to poor blood flow and vein dysfunction. Generally, damaged veins can lead to stagnant blood, increasing the likelihood that a blood clot forms.

Certain conditions, such as obesity, pregnancy, and prolonged standing or sitting, heighten the risk factors for both varicose veins and DVT. However, it’s important to understand that varicose veins are not always a direct cause of DVT. Many people with bulging veins never develop deep vein thrombosis, but their higher risk means close monitoring is essential.

Signs that varicose veins may be progressing toward vein thrombosis include sudden swelling in one leg, pain, red or discolored skin, and increased warmth in the affected area. These could indicate a developing serious condition that demands immediate medical care.

How Are DVT and Varicose Veins Diagnosed?

Accurate diagnosis is essential for proper treatment and prevention of complications related to both deep vein thrombosis and varicose veins. For DVT, healthcare providers may use a combination of ultrasound imaging, D-dimer blood tests, and a physical examination of the affected limb to detect the presence of a blood clot in the deep veins.

In contrast, varicose veins are often diagnosed through a physical exam and ultrasound to evaluate the blood flow and check for any valve dysfunction in the affected veins. In some cases, venography may be used for a more detailed assessment.

If you’re experiencing leg swelling, pain, skin discoloration, or any other early symptoms associated with either condition, it is important to seek medical attention promptly. When left untreated, these conditions can lead to complications like chronic venous insufficiency, venous thromboembolism, and even tissue damage. 

How to Treat DVT vs. How to Treat Varicose Veins

While both deep vein thrombosis (DVT) and varicose veins involve issues with the veins, they differ greatly in terms of risk, urgency, and treatment approach. DVT is a potentially life-threatening condition that requires immediate medical intervention, whereas varicose veins are usually a chronic but manageable issue that affects quality of life more than overall health.

Here’s a closer look at how each condition is treated:

How to Treat Varicose Veins

Varicose vein treatment begins with conservative approaches but can also include minimally invasive procedures depending on the severity. At CACVI, we often follow a complete approach, starting with lifestyle changes like regular exercise, healthy weight maintenance, and elevating the affected leg to improve blood flow and reduce leg swelling. These simple steps help relieve the heavy feeling and discomfort caused by bulging veins and damaged vein valves.

Compression stockings are a first-line treatment option that helps manage symptoms by supporting affected veins, improving circulation, and reducing swelling. Another common treatment is sclerotherapy, where a solution is injected to close off smaller superficial veins. This is particularly helpful for managing spider veins and smaller varicose veins. 

More advanced procedures include laser therapy, which uses targeted light energy to seal swollen veins, and endovenous laser therapy (EVLT), a minimally invasive option that uses thermal energy to treat varicose veins at their source. In severe cases where other treatments don’t work, surgical removal or vein stripping may be necessary to eliminate affected veins that no longer function properly. These treatments are especially beneficial for individuals with increased risk due to family history, prolonged standing, or certain medical conditions like high blood pressure and heart disease.

How to Treat DVT

Unlike varicose veins, deep vein thrombosis is considered a medical emergency that requires immediate medical care. Early treatment is necessary to prevent complications like a pulmonary embolism, where a blood clot breaks free and blocks blood flow to the lungs.

The primary treatment for DVT involves blood thinners (anticoagulants) to prevent the clot from growing and to reduce the risk of new clots forming. In some cases, medications to dissolve the clot (thrombolytics) may be considered, especially if there’s a high risk of tissue damage. For severe blockages, surgical procedures like thrombolysis or thrombectomy may be used to remove the clot and restore proper blood flow in the affected limb.

Compression stockings are also used in DVT management to reduce swelling and prevent post-thrombotic syndrome, a condition that causes chronic pain and skin changes in the affected leg. Elevating the leg can further assist with fluid drainage, while lifestyle modifications such as avoiding prolonged immobility, taking bed rest only as necessary, and maintaining a healthy weight help reduce the risk of developing DVT again.

Need to Consult a Doctor About Your Vein Health?

While varicose veins are typically visible, twisted veins near the surface of the skin that cause discomfort, swelling, and a heavy sensation, deep vein thrombosis (DVT) is a more serious condition involving a blood clot in the deep veins, often in the leg. DVT can lead to life-threatening complications like pulmonary embolism if not treated promptly.

The key difference lies in the severity and location. Varicose veins affect superficial veins, whereas DVT occurs in deep veins and often shows more urgent symptoms like sudden leg swelling, pain, redness, or discolored skin. Despite this, both conditions require medical attention, especially if you’re at increased risk due to factors like prolonged immobility, pregnancy, heart disease, or a family history of vein problems.

Early diagnosis and professional medical advice are critical for both conditions. Catching varicose veins early can prevent them from worsening or contributing to vein thrombosis, while early detection of DVT can be lifesaving. 

Don’t wait until symptoms escalate. Visit our Center for Advanced Cardiac and Vascular Interventions in LA or Contact Us today! 

✓ Medically reviewed by

Dr. Vasim Lala

D.O., FACC, FSCAI, RPVI · Coronary, vascular and structural intervention

Trained at Mount Sinai in New York in advanced coronary, vascular and structural intervention. Focuses on minimally invasive heart and vascular procedures and on preventive cardiology, and writes for the American College of Cardiology.

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Board certification verifiable through the American Board of Internal MedicineLast reviewed September 2026