The Expert Clinician

By Adam Widdison, author of The Expert Clinician

Knowing when, why and how to examine is one thing. Recognising the limits of those findings and interpreting them is another.

This post asks two questions: how accurate is a physical sign, and what does it mean? It follows my earlier posts on performing the examination (“Making the Physical Examination Count”, “Adapting for Diversity” and “From Talking to Examining”).

Know the Purpose of the Examination

Knowing why you are examining focuses your effort, and knowing what to look for improves accuracy and reliability.

Common purposes include discovering, excluding, confirming, understanding, measuring, assessing, screening for and demonstrating a sign (for example, ruling out peritoneal irritation, checking for a mitral regurgitant murmur, or screening for lymphadenopathy).

A clear clinical question helps focus the examination and may make a relevant sign easier to recognise. However, expectations can also introduce bias, so assess findings objectively rather than simply confirming what you anticipate.

Looking for a sign speculatively is more problematic: a “checklist” examination contributes less than one undertaken with purpose.

When Is a Sign Real?

You always see, feel, or hear something, but is it a true abnormality? In other words, how accurate is the examination?

As with investigations, the key measures are sensitivity and specificity (The Theory Behind the Statistics). In practice:

• Most physical signs have modest sensitivity and specificity; very few are both highly sensitive and highly specific.
• Binary signs (present or absent) are generally more reliable than graded or subjective ones.
• To confirm an abnormality, you want a sign with a low false-positive rate (high specificity).
• To exclude an abnormality, you want a sign with a low false-negative rate (high sensitivity).

For example, in a patient with joint pain and morning stiffness, rheumatoid nodules have high specificity for Rheumatoid Arthritis (RA). However, because their sensitivity is low, the absence of rheumatoid nodules does not exclude RA.

Few clinical signs are accurate enough to be diagnostic on their own or to reliably exclude a condition. A sign’s predictive value (The Theory Behind the Statistics) depends heavily on how common the condition is in the tested population: what works well in a high-prevalence specialist setting may perform less well in primary care.

Objective measurements, such as blood pressure under standard conditions, are more reliable and reproducible. Others are more subjective. Heart rate can be hard to count in tachycardia or arrhythmia; pulse pressure is difficult to assess in calcified arteries; tenderness is influenced by patient anxiety and by the temperature of the examiner’s hands.

Measurable signs usually have a reference range, and the further a result falls outside it, the more likely it is abnormal. But many factors influence the measurement itself. Body temperature varies by site, instrument, the patient’s age, time of day, ambient temperature, recent exercise or meals, and hormonal status. Age, activity, fitness, BMI, temperature, alcohol, caffeine, and stress affect blood pressure.

Understanding the Meaning of a Sign

Accuracy is necessary but not sufficient. Interpretation within the full clinical context drives diagnosis and management. 

Identifying a sign is a skill you can improve with technique and practice. 

Interpretation is a proposition: an opinion that carries uncertainty and therefore the risk of error.

The real question is always: what does it mean?

Why Examinations Go Wrong

Unlike laboratory tests, physical examination lacks an external quality-control system. Accuracy depends heavily on prevalence, the examiner’s skill and experience, and the patient’s body type. 

Common process errors

• Haste, distraction, fatigue and multitasking.
• A “checklist” examination performed without purpose or thought.
• Inadequate exposure, poor lighting, examining through clothing, or examining in the wrong position.
• Failing to compare sides.
• Failing to re-examine after changing position.
• Relying on investigations rather than refining clinical skills through deliberate practice.

Common causes of false negatives

• The sign was not sought properly.
• Patient factors (obesity, skin colour).
• Examiner sensory limitations.
• The sign is intrinsically difficult to elicit (early diastolic murmur, subtle tendon reflexes).
• The abnormality is subtle, or the patient has presented early.
• The sign is intermittent and absent at the time of examination.

Common causes of false positives

• Examiner error.
• Patient factors (an easily palpable aorta mistaken for an aneurysm in a thin patient; raised blood pressure due to anxiety).
• Signs that are easy to elicit but clinically insignificant.

Common causes of interpretation error:

• Bias: letting opinion or belief override the evidence, or favouring information that is familiar, readily available, or fits a preconceived idea. For example, alcohol is the cause of acute pancreatitis in approximately 50% of patients, but excessive drinking is also common. In a patient with pancreatitis who drinks, do not assume alcohol is the cause.
• Mis-prioritisation: over- or under-estimating the significance of a sign. For example, tenderness may take priority over weight loss.
• Incorrect associations: assuming cause and effect, or forcing information to fit a pattern. For example, an inguinal hernia may be obvious, but is it causing the vomiting?
• Correlation does not equal causation. Trends over time, such as serial vital signs or blood results, are useful, but should be interpreted with caution. For example, a fall in blood pressure does not necessarily confirm bleeding.
• Over-estimating personal knowledge, opinion or intuition.
• Fear of missing a diagnosis, or failure to make a decision.

Reducing Error

Awareness of common pitfalls is the first defence. 

Recognise the limits of subjective signs and your own limits. Hearing and eyesight decline with age. Colour is subjective, and natural skin tone, ambient light and décor can all affect the detection of jaundice or anaemia. 

Use a standardised technique, double-check, triangulate with other information, and, where helpful, seek a second opinion. For example, bowel sounds vary widely between patients and with listening time: absent sounds do not prove ileus, nor do active sounds prove obstruction, and longer listening improves reliability.

Timing matters. An early presentation may show only subtle signs, while a late one may reveal several overlapping abnormalities. When uncertainty remains, careful, sometimes repeated, review is justified.

Knowledge gaps are inevitable, but knowing where yours are helps direct learning.

An interpretation is more convincing when it aligns with symptoms and risk factors. Inconsistencies should prompt reconsideration rather than dismissing findings that don’t fit.

General principles that improve accuracy

• Expose adequately but modestly, and re-cover promptly. Adapt your technique for age, pain, disability and cultural needs.
• Focus on the systems suggested by the history: the higher the pre-test probability, the more likely a positive finding is real.
• Be systematic yet flexible: respond to unexpected findings.
• The more careful the examination, the more reliable the finding.
• Technically easy-to-identify signs are more likely to be identified; visible abnormalities are easier to detect than palpable ones.
• Measurable, reproducible signs with minimal inter-observer variation (height, weight, blood pressure, temperature, joint range of movement) are more accurate.
• Signs that are present or absent are identified more reliably than those that depend on gradation. Deciding whether a murmur is present is more reliable than judging its loudness.
• The more advanced or obvious the abnormality, the more likely it is to be real.
• The absence of a sign does not exclude the condition.
• Use multiple sources of evidence and cross-check for internal consistency. 
• Reflect, review and, where appropriate, seek a second opinion or multidisciplinary discussion. Be alert to bias and over-diagnosis.
• Training matters, but skills grow with experience and familiarity gained through deliberate practice.
• If in doubt, review.

Key Takeaways

A skilled physical examination combines technical proficiency with empathy and clinical reasoning. 

Examine with purpose; a checklist-based examination adds little.

Always interpret findings in light of the clinical context and the pre-test probability of disease. Recognise the limitations of a sign. 

Guard against bias by reviewing the wider clinical picture, addressing inconsistencies, and seeking a second opinion when appropriate.

When performed thoughtfully, the examination is a key part of the consultation. It helps prevent missed diagnoses and unnecessary over-diagnosis, strengthens the clinician–patient relationship, and remains central to high-quality care.

Clinical consultations are more than information exchange—they demand sharp cognitive skills to interpret symptoms and signs, challenge assumptions, and make sound decisions under pressure.

In the next post, I look at the cognitive skills behind good consultations:

• Why finding an answer isn’t the same as knowing it applies to the patient in front of you
• How mental models speed up our thinking, and when they quietly mislead us
• Why patients’ own mental models matter just as much as ours
• Why we shouldn’t treat every error as an individual failure when fatigue,

I would value your thoughts: 

What examination pitfalls have you encountered in practice, and how do you guard against them?

If you’re interested in developing a more adaptive, patient-centred approach, you can read more here: 

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