Wells Score (DVT & PE) 🩸
Wells score for suspected DVT and PE. Pre-test probability, when to order D-dimer vs imaging, and NICE NG158 next steps for NCHDs.
Why use it
- Wells score estimates pre-test probability of DVT or PE. It guides whether to use D-dimer (to rule out) or go straight to imaging, and helps avoid unnecessary imaging when probability is low.
- Use the calculator above: tap each criterion that applies. Score determines "likely" vs "unlikely"; the tool shows recommended next steps. Follow local protocol (e.g. NICE NG158).
DVT: interpretation and action
≤1
- Interpretation
- DVT unlikely
- Action
- D-dimer. If negative → DVT excluded, no ultrasound. If positive → proximal leg vein ultrasound.
≥2
- Interpretation
- DVT likely
- Action
- Ultrasound within 4 h if possible. If not: D-dimer first (before anticoagulation), then interim therapeutic anticoagulation, then ultrasound within 24 h.
| Score | Interpretation | Action |
|---|---|---|
| ≤1 | DVT unlikely | D-dimer. If negative → DVT excluded, no ultrasound. If positive → proximal leg vein ultrasound. |
| ≥2 | DVT likely | Ultrasound within 4 h if possible. If not: D-dimer first (before anticoagulation), then interim therapeutic anticoagulation, then ultrasound within 24 h. |
PE: interpretation and action
≤4
- Interpretation
- PE unlikely
- Action
- D-dimer (age-adjusted if validated). If negative → PE excluded. If positive → consider CTPA.
>4
- Interpretation
- PE likely
- Action
- Consider CTPA. If haemodynamically unstable, escalate and treat for PE while arranging imaging. Do not use D-dimer to rule out.
| Score | Interpretation | Action |
|---|---|---|
| ≤4 | PE unlikely | D-dimer (age-adjusted if validated). If negative → PE excluded. If positive → consider CTPA. |
| >4 | PE likely | Consider CTPA. If haemodynamically unstable, escalate and treat for PE while arranging imaging. Do not use D-dimer to rule out. |
Important points
- Do not start anticoagulation before D-dimer when using D-dimer to rule out DVT (anticoagulation can lower D-dimer).
- If haemodynamically unstable with suspected PE: escalate immediately; give treatment for PE while organising CTPA.
- Pregnancy, previous VTE on anticoagulation, and other factors may alter pathway; discuss with senior and follow local policy.
Wells Score
Tap each criterion that applies (DVT or PE)
Select all that apply. "Alternative diagnosis at least as likely" subtracts 2 points.
Wells DVT score
0
DVT unlikely (≤1)
Next steps
- D-dimer: if negative, DVT excluded (no imaging needed).
- If D-dimer positive, arrange proximal leg vein ultrasound.
- Follow local protocol / NICE NG158.
Related NICE guidance
NICENICE NG158 — Venous thromboembolic diseases: diagnosis, management and thrombophilia testing
Full guidance on nice.org.uk. BetterCall is not endorsed by NICE.
Educational reference only. Medical disclaimer