History and Physical Examination

History taking and physical examination are the two foundational, low-technology acts of clinical assessment. The history is the structured account of the patient's symptoms, past illnesses, medications, and context elicited through interview; the physical examination is the systematic inspection, palpation, percussion, and auscultation of the body. Together they generate the initial diagnostic hypotheses that direct any further investigation.

Definition

The history and physical examination are the interview-based collection of a patient's health account and the systematic clinical examination of the body, performed together to form the initial basis for diagnosis and management.

Scope

This entry covers the components and diagnostic logic of the clinical history and physical examination as a reference topic — the structure of the history, the maneuvers of the examination, and how their findings carry diagnostic weight. It treats the examination as a method of information gathering and does not provide instructions for examining any specific patient or condition.

Core questions

• What information does the history contribute relative to the examination and tests?
• How is the clinical history conventionally structured?
• How are the accuracy and reproducibility of physical signs assessed?
• How do findings translate into diagnostic probabilities?

Key concepts

• History of present illness
• Review of systems
• Past medical, medication, and allergy history
• Inspection, palpation, percussion, auscultation
• Sensitivity, specificity, and likelihood ratios of signs
• Inter-observer reliability
• Hypothesis-driven examination

Mechanisms

The clinician first elicits a history — present illness, prior conditions, medications, and relevant context — which generates a small set of diagnostic hypotheses. The physical examination is then directed by those hypotheses, with specific findings raising or lowering the probability of candidate diagnoses. The evidentiary value of any sign depends on its sensitivity, specificity, and likelihood ratios, and on how reproducibly different examiners elicit it. In Hampton's classic outpatient study the history alone led to the eventual diagnosis in the large majority of cases, with examination and investigations contributing incrementally.

Clinical relevance

The history and examination are the entry point of nearly every clinical encounter and a core competency taught throughout health-professions education. As a reference topic this entry explains how these data are gathered and weighed; it is descriptive of the method and is not a substitute for supervised clinical training or for examining any particular patient.

Evidence & guidelines

Empirical study of the clinical examination has shown that the history carries substantial diagnostic yield: Hampton and colleagues found it produced most diagnoses among general-medical outpatients. The evidence-based-examination tradition, articulated by Sackett and developed in reference compendia such as McGee's Evidence-Based Physical Diagnosis, quantifies the precision, accuracy, and likelihood ratios of individual physical signs so that examination findings can be interpreted probabilistically rather than categorically.

History

Structured history and physical examination matured as the cornerstone of clinical method over the nineteenth and twentieth centuries, with the addition of instruments such as the stethoscope. Hampton's 1975 study quantified the relative diagnostic contributions of history, examination, and tests, and from the 1990s the evidence-based examination movement, led by Sackett's rational-clinical-examination work, reframed physical signs in terms of measured diagnostic accuracy.

Debates

Is the physical examination being displaced by imaging and laboratory testing?

Studies show the history yields most diagnoses and that many physical signs have modest, variable accuracy, fuelling debate over how much examination skill remains essential when investigations are readily available; evidence-based diagnosis argues for retaining signs with demonstrated discriminatory value.

Key figures

• John R. Hampton
• David L. Sackett
• Steven McGee
• Lynn S. Bickley

Seminal works

• hampton-1975
• sackett-1992
• mcgee-2018

Frequently asked questions

Which contributes more to diagnosis, the history or the physical examination?

Empirical studies such as Hampton's found that the history alone yields the eventual diagnosis in most general-medical outpatients, with the examination and investigations contributing incremental and confirmatory information.

Why are likelihood ratios used to describe physical signs?

Likelihood ratios express how much a present or absent sign shifts the probability of a diagnosis, allowing examination findings to be combined with pre-test probability rather than treated as simply positive or negative.