VENOUS DISEASE

Swollen legs, varicose veins, deep vein thromboses, ulcers and more…

DEEP VEIN THROMBOSIS (DVT)

Blood Clots in the Legs — Symptoms, Diagnosis and Treatment in Singapore

What Is a Deep Vein Thrombosis?

A deep vein thrombosis (DVT) is a blood clot that forms in the deep veins, most commonly in the legs or pelvis. These veins sit beneath the muscles and are responsible for returning blood back to the heart.

When a clot forms, it can partially or completely obstruct blood flow, causing pain, swelling and long-term damage.

A DVT is a significant medical condition because the clot can break off and travel to the lungs, resulting in a pulmonary embolism (PE) — a potentially life-threatening emergency.

DVT and PE together are known as venous thromboembolism (VTE).

Why Do DVTs Form?

A DVT occurs when one or more of the following factors are present:

Reduced blood flow (stasis)

  • Prolonged sitting or immobility

  • Long-haul flights

  • Bed rest or hospital stay

  • Leg paralysis or reduced mobility

Changes to blood composition (hypercoagulability)

  • Cancer

  • Pregnancy and the postpartum period

  • Hormone therapy or oral contraceptives

  • Genetic clotting disorders (e.g., Factor V Leiden)

  • Smoking

  • Dehydration

Injury or inflammation of the vein wall

  • Recent surgery

  • Trauma

  • Infection

  • Intravenous catheters

Common Signs and Symptoms of DVT

A DVT can be silent, but when symptoms occur, they may include:

  • Leg swelling (usually one-sided)

  • Pain or tenderness, often in the calf or thigh

  • Warmth or redness over the affected area

  • Heaviness or tightness in the leg

  • Discomfort when walking

Some patients have no symptoms at all, and the first sign is a complication such as a pulmonary embolism.

Why DVT Can Be Dangerous — Pulmonary Embolism (PE)

A clot in the leg can break loose and travel to the lungs, causing a pulmonary embolism.

Symptoms include:

  • Sudden shortness of breath

  • Chest pain

  • Rapid heartbeat

  • Light-headedness or fainting

PE requires urgent medical attention.

Around 60% of VTE events occur in hospital, making DVT and PE the leading preventable cause of hospital-related death.

How DVT Is Diagnosed

Diagnosis usually involves:

1. Clinical assessment

Evaluation of symptoms, risk factors and examination findings.

2. Duplex ultrasound

The gold-standard test used to confirm a DVT, assess clot extent and evaluate venous flow.

3. Blood tests

A D-dimer test may support the diagnosis in low-risk patients, but imaging is essential for confirmation.

4. Additional imaging (selective cases)

CT or MR venography may be used for pelvic or abdominal clots.

Treatment Options for DVT

Treatment depends on clot location, severity, symptom burden and patient risk profile.

1. Anticoagulation (blood thinners)

This is the mainstay of DVT treatment.

Common medications include:

  • Rivaroxaban (Xarelto)

  • Apixaban

  • Heparin or LMWH

  • Warfarin (less common today)

Anticoagulation prevents the clot from growing and reduces the risk of PE.

2. Catheter-Directed Thrombolysis (CDT)

A minimally invasive treatment where clot-dissolving medication is delivered directly into the clot.

Useful for:

  • Extensive iliofemoral DVT

  • Severe symptoms

  • Threatened limb

  • Young or active patients to reduce long-term damage

3. Mechanical Thrombectomy

Devices that mechanically remove or break up the clot.

Often used with or without thrombolysis, depending on clot age and patient risk.

4. Venous Stenting

If a narrowed or compressed pelvic vein is found (e.g., May–Thurner syndrome), a stent may be placed to restore blood flow and prevent recurrence.

5. Compression therapy

Compression stockings help reduce swelling and lower the risk of post-thrombotic syndrome, a chronic complication that causes pain, swelling and skin changes.

Post-Thrombotic Syndrome (PTS)

Around 20–50% of patients develop PTS after a DVT.

Symptoms include:

  • Chronic leg swelling

  • Heaviness or aching

  • Skin discoloration

  • Development of venous ulcers in severe cases

Early diagnosis and optimal DVT treatment significantly reduce PTS risk.

When to Seek Medical Help

You should see a vascular surgeon or seek urgent medical attention if you experience:

  • Sudden, unexplained leg swelling

  • Pain in the calf or thigh

  • Warm, red or tender leg

  • Shortness of breath or chest pain

  • Fainting or collapse

Prompt diagnosis and treatment help prevent long-term complications and improve outcomes.

DVT Care in Singapore

As a vascular and endovascular surgeon in Singapore, I manage the full spectrum of DVT — from diagnosis and medical treatment to minimally invasive clot removal and long-term venous care.

Treatment is tailored to each patient based on anatomy, risk factors and clinical presentation, using advanced imaging and modern endovascular techniques.

Frequently Asked Questions (FAQ)

Is DVT the same as a blood clot?

Yes. DVT refers to a blood clot forming in the deep veins.

Can DVT happen without symptoms?

Yes — many DVTs are silent.

How long must I take anticoagulation?

Usually 3–6 months, depending on clot type and risk factors.

Can I exercise with a DVT?

Walking is usually encouraged, but heavy exercise should be discussed with your doctor.

Is DVT life-threatening?

The clot itself can cause long-term leg damage, but the main danger is if it travels to the lungs, causing a PE.

Summary

A deep vein thrombosis is a serious but treatable condition.

Early recognition, accurate diagnosis and appropriate treatment — whether medical or minimally invasive — can reduce complications and protect long-term vein health.

If you are experiencing symptoms such as leg swelling, pain or sudden shortness of breath, seek prompt medical attention.