Wells Score for Pulmonary Embolism

Calculate the Wells score for pulmonary embolism and see whether PE is likely or unlikely, with the matching diagnostic pathway. Educational tool only.

Tick every criterion that applies

Points are fixed by the score; only the criteria present are counted.

Clinical signs of DVT (leg swelling and pain with palpation of the deep veins)3PE is the most likely diagnosis (or equally likely to another diagnosis)3Heart rate > 100 beats/min1.5Immobilisation for ≥ 3 days, or surgery in the previous 4 weeks1.5Previous confirmed pulmonary embolism or DVT1.5Haemoptysis1Active malignancy (treated in the last 6 months, or palliative)1

Wells score (PE)

0 / 12.5

Weighted seven-item score

Two-tier interpretation

PE unlikely

PE is unlikely (score ≤ 4). The pathway is a D-dimer first; if it is negative, PE can be considered excluded, and imaging is only needed if the D-dimer is raised.

The Wells score for pulmonary embolism comes from Wells and colleagues (2000) and is presented here in the modified weighted form used in current UK pathways, where a total above 4 means PE is “likely” and the score is 4 or below means “unlikely”. An “unlikely” score does not exclude PE on its own — it selects the D-dimer-first pathway, and imaging is still needed if the D-dimer is raised. The score assumes a patient in whom PE is being considered, and does not apply to haemodynamically unstable patients, who need immediate assessment outside this pathway.

Frequently asked questions

What is the Wells score for pulmonary embolism?

It is a weighted clinical prediction rule that estimates pre-test probability when pulmonary embolism is being considered. The modified two-tier form classifies a score above 4 as PE likely and 4 or below as PE unlikely.

Does a PE-unlikely Wells score rule out pulmonary embolism?

No. In the two-tier pathway, PE unlikely normally leads to D-dimer testing first. Imaging may still be required if the D-dimer is raised or the clinical situation warrants it.

What is the Wells PE cutoff used in UK pathways?

The commonly used modified two-tier cutoff is greater than 4 for PE likely and 4 or less for PE unlikely. Local guidance and clinical judgement still take precedence.

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