Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE) are serious but treatable blood clot conditions. Together they are known as Venous Thromboembolism (VTE) — one of the leading causes of preventable hospital death in the UK, affecting around 60,000 people per year. Understanding the warning signs and getting prompt treatment can be life-saving.
What Is DVT?
Deep Vein Thrombosis (DVT) occurs when a blood clot forms in one of the deep veins of the body — most commonly in the leg. The clot can partially or completely block blood flow, causing pain, swelling, and potentially dangerous complications if it breaks free and travels to the lungs.
What Is Pulmonary Embolism (PE)?
A pulmonary embolism happens when a blood clot — often from a DVT — travels through the bloodstream and lodges in the pulmonary arteries of the lungs. This blocks blood flow and can be life-threatening. PE is a medical emergency requiring immediate treatment.
Symptoms of DVT
- Pain, aching, or tenderness in one leg (usually calf or thigh)
- Swelling in one leg, ankle, or foot
- Warm skin around the affected area
- Red or darkened skin over the clot
- Visible surface veins appearing more prominent
DVT can sometimes occur with no symptoms, making it difficult to detect without medical investigation.
Symptoms of Pulmonary Embolism
- Sudden breathlessness or difficulty breathing
- Sharp chest pain (often worse when breathing in)
- Rapid heart rate (palpitations)
- Coughing up blood
- Feeling faint, dizzy, or collapsing
- Clammy or bluish skin
Call 999 immediately if you or someone else shows signs of a pulmonary embolism. This is a life-threatening emergency.
Risk Factors for DVT and PE
- Prolonged immobility (long-haul flights, bed rest, sitting for long periods)
- Recent surgery — especially orthopaedic procedures (hip, knee replacement)
- Cancer and cancer treatments
- Pregnancy and up to 6 weeks after giving birth
- Obesity (BMI over 30)
- Combined oral contraceptive pill or HRT
- Previous DVT or PE
- Family history of blood clotting disorders (thrombophilia)
- Age over 60
- Smoking
- Dehydration
How Is DVT Diagnosed?
If DVT is suspected, your GP will likely refer you urgently to hospital for investigation. Diagnosis typically involves:
- D-dimer blood test — measures a substance released when blood clots break down; a negative result can rule out DVT
- Ultrasound scan — uses sound waves to detect clots in leg veins (the standard diagnostic test)
- Venogram — an X-ray using dye injected into the vein (used in complex cases)
How Is PE Diagnosed?
- CT pulmonary angiogram (CTPA) — the main imaging test for PE, producing detailed pictures of lung blood vessels
- V/Q scan — measures ventilation and perfusion of the lungs; used when CTPA cannot be performed (e.g., pregnancy)
- Echocardiogram — ultrasound of the heart to assess its function under strain
- Chest X-ray and ECG — to rule out other causes of chest pain and breathlessness
NHS Treatment for DVT
The main treatment for DVT is anticoagulant medication (blood thinners), which prevents the clot from growing and reduces the risk of PE. NHS options include:
- Apixaban (Eliquis) or Rivaroxaban (Xarelto) — Direct Oral Anticoagulants (DOACs), taken as tablets; now the first-line treatment for most patients
- Warfarin — requires regular INR blood tests to monitor dosage; still used in some cases
- Low Molecular Weight Heparin (LMWH) — injections used initially or for patients with cancer
Treatment typically lasts 3–6 months for a first DVT, and longer (sometimes lifelong) if there is an ongoing risk factor such as cancer or thrombophilia.
NHS Treatment for Pulmonary Embolism
- Anticoagulants — same as for DVT; most patients are treated with DOACs
- Thrombolysis (clot-busting drugs) — given for massive or high-risk PE where blood pressure is critically low
- Surgical embolectomy — rarely used; removes the clot from the pulmonary artery in life-threatening cases
- IVC filter — a filter placed in the main vein to catch clots; used when anticoagulants cannot be given
Compression Stockings for DVT
Previously, graduated compression stockings were routinely prescribed after DVT to prevent post-thrombotic syndrome (PTS). Current NHS/NICE guidance no longer routinely recommends them for all DVT patients, though they may still be advised for symptom relief or in specific circumstances. Discuss with your clinical team.
Preventing DVT: Travel and Hospital
During Long-Haul Travel
- Move your legs regularly — walk around the cabin every hour
- Do calf-raise exercises in your seat
- Stay hydrated — avoid excessive alcohol
- Wear below-knee compression stockings if you’re at moderate/high risk
- Consider LMWH injections for high-risk patients (discuss with GP)
In Hospital
- All hospital patients are assessed for VTE risk on admission
- Anti-embolism stockings, pneumatic compression devices, or prophylactic LMWH injections are given as appropriate
- Early mobilisation after surgery is strongly encouraged
Long-Term Outlook After DVT or PE
Most people with DVT or PE recover fully with treatment. However, there are some ongoing considerations:
- Post-thrombotic syndrome (PTS) — some people develop chronic leg pain, swelling, and skin changes after DVT
- Chronic thromboembolic pulmonary hypertension (CTEPH) — a rare but serious complication where scarring from a PE causes raised blood pressure in the lungs
- Recurrence risk — the risk of another DVT or PE is higher after a first event, particularly in the first 2 years
When to Seek Emergency Help
Call 999 if you have any symptoms of PE (sudden chest pain, breathlessness, coughing blood, collapse). Call 111 or see your GP urgently if you have a painful, swollen leg that may indicate DVT. Early treatment is essential to prevent life-threatening complications.
Related Health Guides on YourHealthXpert
Explore these related NHS-aligned health guides:
- Heart Attack Guide — DVT and pulmonary embolism share cardiovascular risk factors with heart attack; understand how clotting disorders affect overall heart health.
- Atrial Fibrillation Guide — AF and DVT both involve clotting risk; learn how anticoagulants are used across both conditions in NHS care.
- High Blood Pressure Guide — Hypertension is a risk factor for vascular disease including DVT; understand the NHS approach to cardiovascular risk reduction.
- Long COVID Guide — COVID-19 significantly increases DVT and pulmonary embolism risk; understand the post-COVID clotting cascade and NHS monitoring.
- Stroke Guide — Stroke and PE can both result from clots in the bloodstream; learn the warning signs and NHS emergency pathways.
- High Cholesterol Guide — Raised cholesterol contributes to vascular inflammation that increases clot risk; learn about the NHS approach to lipid management.