Synopsis
Integrate a patient's account, targeted examination and contextual evidence into a ranked differential diagnosis, an explicit uncertainty statement and a safe next-step plan.
- Begin with the patient's agenda and an open account, then define chronology, severity, functional change and urgent symptoms before narrowing the enquiry.
- Generate a small set of mechanistic hypotheses during the history and choose examination components that can discriminate among them or detect immediate risk.
- Separate facts from interpretations: symptoms are reported, signs are observed under stated conditions, and diagnoses remain weighted explanations until adequately supported.
Reasoning priorities
Compress the case into features that influence probability and urgency.
Revise the sentence as new evidence arrives; a representation that still reflects the first impression despite discordant data promotes anchoring.
Worked reasoning
A fictional case supplies sudden pleuritic chest pain after recent leg immobilisation, mild tachycardia, normal chest auscultation, no reproducible chest-wall tenderness and oxygen saturation below the person's documented baseline.
- Recognise the change in oxygenation and sudden symptoms as priority evidence, obtain complete observations and decide whether the patient needs urgent assessment before extending the history.
- Represent the case as acute pleuritic chest pain with impaired oxygenation and thromboembolic context, noting that normal auscultation does not explain or exclude the syndrome.
- Rank pulmonary embolic disease highly while retaining pneumothorax, infection, cardiac causes and chest-wall pain; use the absence of reproducible tenderness only as modest evidence.
- Choose the appropriate acute clinical pathway and probability-based testing rather than ordering unrelated panels, while addressing current physiological needs and explaining why urgent evaluation is proposed.
- Verify that all stated facts were supplied, invite the patient to correct the timeline, document escalation and use feedback to examine whether normal auscultation caused false reassurance.