1 A Framework for Clinical Reasoning

The clinical reasoning sequence

Clinical reasoning turns a patient’s story and findings into a safe, revisable plan. A practical sequence is to define the problem, identify immediate risks, assess systematically, make and communicate decisions, and then reassess and arrange follow-up.

If a patient is unstable, stabilization and getting help take priority over completing a diagnostic workup. Apply the framework alongside your training, local protocols, and scope of practice.

Define the problem

Begin with the patient’s main concern and the reason for assessment. Gather the history, relevant medical conditions and medications, baseline function, and the patient’s perspective. Ask focused questions about onset, progression, associated symptoms, and important risk factors; use collateral information when needed.

Summarize the case in a concise Problem representation. For example: “An older adult with sudden shortness of breath, low oxygen saturation, and a rapid respiratory rate.” The summary focuses the reasoning without prematurely declaring a diagnosis.

Identify immediate risks

First determine whether the patient is critically ill or deteriorating. Assess overall appearance and responsiveness, obtain vital signs, and promptly call for appropriate help when there is serious concern.

For a deteriorating patient, use ABCDE—Airway, Breathing, Circulation, Disability, Exposure—to identify and address threats in order. Treat life-threatening problems as they are found; do not wait until the entire assessment is complete. Reassess the effects of each intervention.

Vital signs and their trends help reveal risk, but no score or single reassuring measurement replaces clinical judgment. In acute hospital settings, monitoring plans should specify which observations to record and how often. Abnormal findings or clinical concern should prompt a response and appropriate escalation.

Assess and prioritize explanations

Once immediate threats are addressed—or in parallel with stabilization when the team allows—complete a focused history and examination. Select tests to answer a clinical question, such as whether a suspected condition is more or less likely, or whether the result would change treatment or disposition.

Develop a Prioritized differential rather than an unranked list. Include:

• Most likely explanations that fit the overall pattern.

• Must-not-miss conditions that could cause rapid harm if overlooked.

• Important alternatives suggested by risk factors, atypical features, or findings that do not fit the leading explanation.

For each possibility, compare findings that support it, findings that argue against it, and information still needed. Keep uncertainty visible: a Working diagnosis is a current explanation, not proof. Reconsider it when new evidence conflicts with it, and use decision-support tools, consultation, or a second opinion when useful.

For sudden shortness of breath, first assess and address airway, breathing, and circulation threats. The differential may include pulmonary embolism, pneumothorax, pneumonia, heart failure, or a cardiac cause. History, examination, vital signs, and targeted tests help prioritize these possibilities; the patient’s stability determines how urgently to investigate and escalate.

Make and communicate decisions

Turn the assessment into a clear plan that addresses:

1. What needs to happen now to stabilize the patient or address an urgent threat.

2. What evaluation is needed to clarify the diagnosis.

3. Where and how closely the patient should be monitored, including when to seek senior or specialist help.

4. What would change the plan, including signs of deterioration or failure to improve.

Communicate concerns and requests clearly. Use a structured handoff such as SBAR (Situation, Background, Assessment, Recommendation) when appropriate. Document key findings, reasoning, actions, response, and outstanding questions. Assign a specific person responsibility for reviewing and communicating pending test results.

Reassess and arrange follow-up

Clinical reasoning is iterative. After an intervention, reassess at an interval suited to the patient’s risk and to how quickly the intervention should work. Compare current symptoms, examination, and vital signs with the baseline and the expected response.

If the patient worsens, fails to improve as expected, or develops findings that do not fit the current explanation, escalate care and reconsider the differential. Check treatment effects regularly and seek help early when needed.

Before ending an encounter or transferring care, clarify the monitoring plan, follow-up arrangements, who owns pending results, and what should trigger urgent reassessment. Involve the patient and, when appropriate, family or caregivers in understanding the plan and raising concerns.