Wells Score Calculator (PE)

The Wells Score is a validated clinical decision tool used to estimate the pre-test probability of pulmonary embolism (PE) in patients presenting with suggestive symptoms. It assigns points to seven clinical criteria and stratifies patients into Low, Moderate, or High risk categories to guide diagnostic workup.

A pulmonary embolism is a blockage in one or more of the arteries in the lungs, most commonly caused by blood clots that travel from the deep veins of the legs (deep vein thrombosis, or DVT). PE can be life-threatening if not diagnosed and treated promptly, making early risk stratification tools like the Wells Score critical.

The seven Wells criteria are: (1) clinical signs of DVT (+3 pts), (2) PE is the most likely diagnosis (+3 pts), (3) heart rate > 100 bpm (+1.5 pts), (4) immobilization ≥ 3 days or recent surgery (+1.5 pts), (5) previous DVT/PE (+1.5 pts), (6) hemoptysis (+1 pt), and (7) active malignancy (+1 pt). The maximum possible score is 12.5.

A score of 0–1 indicates Low probability (PE prevalence ~1–3%), a score of 2–6 indicates Moderate probability (~16–28%), and a score ≥ 7 indicates High probability (~38–67%). Low-risk patients may be evaluated with a D-dimer test alone, while higher-risk patients typically require CT pulmonary angiography (CTPA).

Common symptoms of PE include sudden shortness of breath, sharp chest pain (often worse with breathing), rapid heart rate, coughing (sometimes with blood), lightheadedness, and leg pain or swelling. Symptoms can vary widely and PE can present without any classic signs, which is why structured scoring tools like Wells are important.

No — the Wells Score alone cannot rule out PE. In low-risk patients (score ≤ 1), a negative D-dimer result together with the low Wells Score can effectively exclude PE without further imaging. However, the Wells Score is a risk stratification tool, not a diagnostic test, and must always be used alongside clinical judgment.

The Wells Score was developed by Dr. Philip S. Wells and colleagues and first published in 1998. It was later refined and validated in multiple large prospective studies, becoming one of the most widely used and evidence-based tools for pre-test probability assessment of pulmonary embolism worldwide.

No. This calculator is intended as a clinical decision support aid for healthcare professionals and should not replace a thorough history, physical examination, and clinical judgment. Always consult appropriate clinical guidelines and specialist expertise when evaluating a patient for suspected pulmonary embolism.