“DVT is one of the most dangerous conditions that gets dismissed as a sprained muscle. A swollen, painful leg after long travel or surgery is never something to walk off and hope for the best.”
Written by Dr Rahul Agarwal, Consultant Vascular & Endovascular Surgeon
CARE Hospitals, Banjara Hills, Hyderabad
Deep vein thrombosis (DVT) occurs when a blood clot forms in one of the deep veins of the body — most commonly the leg. Left untreated, part of the clot can break off and travel to the lungs, causing a pulmonary embolism (PE) — a potentially fatal condition. DVT and PE together form venous thromboembolism (VTE), one of the leading preventable causes of hospital death worldwide.
🦠 Who Gets DVT?
DVT is more common than most people realise. Risk factors include prolonged immobility (long-haul flights, bed rest), recent surgery (especially hip or knee replacement, abdominal surgery), cancer, pregnancy, oral contraceptive pills, inherited clotting disorders (thrombophilia), obesity, and previous DVT.
🦥 Symptoms of DVT
- Swelling of the calf, ankle, or entire leg — usually one leg only
- Pain or tenderness in the calf or thigh
- Warmth and redness over the affected area
- A feeling of heaviness or tightness in the leg
Importantly, up to 50% of DVTs cause no symptoms at all — which is why a high index of suspicion in at-risk patients is essential.
⚠️ Pulmonary Embolism — The Life-Threatening Complication
When a DVT clot dislodges and travels to the lungs, it blocks pulmonary arteries — causing sudden breathlessness, chest pain, rapid heart rate, and in severe cases, collapse and death. Pulmonary embolism is a medical emergency. Suspect it whenever a patient with leg symptoms suddenly develops breathlessness or chest pain.
🔬 Diagnosis
- Duplex Ultrasound — The primary investigation for DVT. Rapid, non-invasive, and highly accurate.
- D-Dimer Blood Test — A negative D-dimer effectively rules out DVT in low-risk patients. A positive result requires imaging confirmation.
- CT Pulmonary Angiography (CTPA) — The gold standard for diagnosing pulmonary embolism.
💉 Treatment
Anticoagulation (Blood Thinners)
The cornerstone of DVT treatment. Anticoagulants (heparin, low molecular weight heparin, warfarin, or the newer direct oral anticoagulants such as rivaroxaban or apixaban) prevent the clot from growing and allow the body’s own systems to gradually dissolve it. Most patients with DVT are treated with oral anticoagulants for 3–6 months.
Catheter-Directed Thrombolysis (CDT)
For extensive DVT involving the iliofemoral veins (the large veins of the thigh and pelvis), catheter-directed thrombolysis may be offered. A catheter is threaded into the clot and clot-dissolving drugs (thrombolytics) are delivered directly, breaking down the clot faster than anticoagulation alone. This reduces the risk of long-term post-thrombotic syndrome.
IVC Filter
In patients where anticoagulation is contraindicated (e.g., active bleeding, recent surgery), an inferior vena cava (IVC) filter can be placed to catch any clots before they reach the lungs. This is a temporary measure in most cases.
❓ Frequently Asked Questions
Can DVT go away on its own without treatment?
Technically, small clots may partially resolve, but untreated DVT carries a significant risk of pulmonary embolism and long-term post-thrombotic syndrome (chronic leg swelling, skin changes, ulcers). Treatment is always recommended.
How long do I need to take blood thinners?
For a first DVT with a clear trigger (e.g., surgery or travel), 3 months is usually sufficient. For recurrent DVT or DVT in patients with cancer or thrombophilia, longer treatment may be recommended. Your haematologist and vascular surgeon will advise based on your individual circumstances.
💡 Key Insight: A swollen, painful leg — especially after surgery, long travel, or a period of immobility — needs a duplex ultrasound the same day. DVT is treatable and preventable. But only if you take it seriously from the start.
📖 Related Reading:
- Catheter-Directed Thrombolysis for DVT
- When Should You See a Vascular Surgeon?
- What Is Vascular Surgery? The Complete Guide
About the Author 🧑🏻⚕️
Dr Rahul Agarwal is a Consultant Vascular & Endovascular Surgeon at CARE Hospitals, Banjara Hills, Hyderabad.