Warning Signs of PE
Call 999 / 911 if you haveSudden breathlessness (unexplained) | Chest pain that worsens with breathing | Coughing up blood | Rapid heart rate with breathlessness | Feeling faint or collapsing. Do not drive — PE can cause sudden collapse.
Risk Factors for PE (Virchow's Triad)
| Risk Category | Examples |
|---|---|
| Stasis (blood not moving) | Long-haul flight, bed rest >3 days, hospitalisation, pregnancy |
| Hypercoagulability (blood clots too easily) | Oral contraceptive pill, HRT, cancer, thrombophilia, dehydration |
| Vessel wall damage | Surgery, trauma, IV catheter, fractures |
How PE Is Diagnosed
| Test | Purpose |
|---|---|
| D-dimer blood test | If low probability — a negative D-dimer rules out PE with 99% sensitivity |
| CT pulmonary angiogram (CT-PA) | Gold standard — shows the clot directly |
| V/Q scan | Alternative to CT-PA in pregnancy |
| ECG | Classic 'S1Q3T3' pattern; more commonly just sinus tachycardia |
| Echocardiogram | Shows right heart strain — indicates massive PE |
| Troponin + BNP | Raised in large PE — indicates right heart strain and severity |
DVT Clue80% of PEs come from a DVT (deep vein thrombosis) in the leg. Look for a red, warm, swollen calf. If you have leg swelling PLUS breathlessness — go to A&E immediately — this combination is highly suspicious for PE.
Wells Score for PE — Quick Assessment
| Clinical Feature | Points |
|---|---|
| Clinical signs of DVT (swollen leg) | 3 points |
| Alternative diagnosis less likely than PE | 3 points |
| Heart rate >100 bpm | 1.5 points |
| Immobilisation ≥3 days or surgery in last 4 weeks | 1.5 points |
| Previous DVT or PE | 1.5 points |
| Haemoptysis (coughing blood) | 1 point |
| Cancer (active or treated in last 6 months) | 1 point |
| Score ≤4 = low probability | Score >4 = PE likely | — |
How long is treatment for PE?
At least 3 months anticoagulation. If unprovoked (no identifiable cause), 6–12 months or indefinite is often recommended due to high recurrence risk.
Can I fly after a PE?
Most guidelines recommend waiting at least 4 weeks after a PE before flying. After 3 months of treatment with a stable condition, short flights are generally safe with compression stockings and hydration.
What is a 'massive PE'?
A massive PE causes haemodynamic instability — low blood pressure, shock, or cardiac arrest. Treatment requires urgent thrombolysis (clot-busting drugs) or catheter-directed thrombectomy in an intensive care setting.
Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.