--- module: 071-02 language: en chapter: 71 title: "Primary Care, Prevention, Multimorbidity, and Continuity" module_title: "History, examination, diagnostic strategy, differential diagnosis, and common disease" source_sha256: 7638e250c8c06d885b06c9f53a981e584b47dd1bd33ca4d1e9b785c7df48248a --- # Primary-care diagnosis and common disease ## Consultation and hidden agenda ### Low prevalence, early atypical presentation ### Treat, test, observe, refer, or prevent ### Identify all concerns before the first in depth #### Safe symptom may precede real fear #### Ask hopes and worries to avoid late surprises ### Fresh history, not only the record ### Negotiate priorities when time is short #### Danger first, then patient priority, prevention #### Unresolved concerns get named follow-up ## Probability at low prevalence ### Pre-test probability from age, risk, setting ### Good tests yield false positives in low risk ### Thresholds: observe, test, or treat #### Lower when delay dangerous, treatment safe #### Higher when treatment harmful, diagnosis unsure ### Decision rules only in validated populations #### A score is evidence, not the decision-maker ## Selective but complete examination ### Observations when systemic illness possible ### Focused is not rushed #### Include systems for danger and alternatives ### Serial examination informs evolving illness ### Record meaningful negatives ### Telehealth limits: arrange in-person care ### Chaperone, consent, trauma-informed care #### Confidential enquiry despite support person ## Common chronic disease and secondary causes ### Hypertension: technique, repeats, home readings #### White-coat and masked patterns differ #### Young onset, resistance, hypokalaemia: secondary ### Diabetes: glucose or glycated haemoglobin #### Variants, anaemia, pregnancy distort the value #### Consider autoimmune or monogenic diabetes ### Lipids interpreted by absolute risk #### Very high LDL cholesterol suggests familial disease #### Severe triglycerides risk pancreatitis ### Chronic kidney disease needs persistence #### Do not mislabel acute change as chronic ## Respiratory and cardiovascular symptoms ### Chronic cough: broad causes, escalate alarms #### Normal chest imaging excludes not everything ### Asthma: show variable airflow limitation #### Normal spirometry does not exclude it #### Check inhaler technique before failure label ### Chest pain: coronary, embolic, aortic, other causes #### Atypical ischaemia, but physiology over stereotype ### Palpitations: correlate symptom with rhythm #### Normal resting trace misses intermittent arrhythmia #### Device matched to event frequency ## Pain and fatigue without polarisation ### Persistent pain has mixed contributors #### Imaging abnormalities common when asymptomatic #### Opioid escalation without function adds harm ### Fatigue: separate sleepiness, weakness, dyspnoea #### Revisit the model, do not expand panels ### Post-infectious symptoms #### Avoid forced graded activity if it worsens #### Pacing and tailored rehabilitation ## Cancer detection and safety-netting ### Alarm symptoms individually non-specific #### Combinations, duration, age, trajectory decide ### Negative screen is not diagnostic reassurance ### Referral states concern, negatives, urgency ### Safety-net: course, warnings, timeframe, return #### Assign responsibility for pending results #### Non-attendance triggers proportionate follow-up ## Mental health and substance use ### Diagnosis by pattern, not questionnaire alone ### Ask about mania before antidepressants ### Direct suicide enquiry does not create intent ### Non-judgemental alcohol and drug assessment #### Alcohol or benzodiazepine withdrawal dangerous #### Care without prior commitment to abstinence ### Breadth first, then selective depth