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).

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.

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.

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.

Tap each criterion that applies (DVT or PE)

Select all that apply. "Alternative diagnosis at least as likely" subtracts 2 points.

Wells DVT score

DVT unlikely (≤1)

Next steps