General Diagnosis
Core approach
General diagnosis is a structured process: chief complaint, history of present illness, past medical/surgical/family/social history, review of systems, vital signs, and a focused physical exam. Characterize symptoms by onset, location, quality, severity, timing, aggravating and relieving factors, and associated symptoms. Build a prioritized differential diagnosis and use pretest probability. Tests move probability; they do not replace clinical reasoning. Screening tests tend to be sensitive, while confirmatory tests tend to be specific.
Concepts to know
Understand red flags, system-based review, risk factors, and illness scripts. Recognize that older adults, immunocompromised patients, and pregnant patients may present atypically. Vital-sign thresholds matter: fever, hypotension, tachycardia, hypoxia, or altered mental status require urgent evaluation.
Question traps
Common traps include anchoring on a musculoskeletal label before excluding systemic disease, ignoring red flags, overreading a single abnormal laboratory value, and confusing a screening test with a diagnostic test. Another trap is treating a normal exam as proof of benign disease when the history is high risk.
Worked example
A 58-year-old smoker reports exertional chest pressure radiating to the jaw and relieved by rest. This is not “just costochondritis” until cardiac ischemia is excluded. Obtain an ECG and arrange emergency assessment. Rule of thumb: rule out the worst first; red flags override a reassuring musculoskeletal exam.
Documentation
Record pertinent positives and negatives, the differential diagnosis, and the follow-up plan. If a benign cause cannot be identified confidently, refer or escalate care.