Organ-System Disorders
Core content
Organ-system questions are broad, so use a framework: presentation, red flags, first-line tests, and management principles. In cardiology, distinguish innocent murmurs-soft, systolic, positional, asymptomatic-from pathologic murmurs that are diastolic, loud, harsh, associated with clicks, or accompanied by failure to thrive, cyanosis, or exercise intolerance. In nephrology, know that isolated proteinuria can be orthostatic and that hematuria with hypertension or edema suggests glomerulonephritis. In neurology, classify seizures and recognize status epilepticus. In hematology, interpret microcytic anemia with iron studies. In endocrinology, distinguish constitutional delay from growth hormone deficiency.
Traps
Do not anchor on a benign diagnosis when red flags are present. A murmur with a click or a family history of sudden death needs echocardiography. Vomiting in an infant can be reflux, but bilious vomiting is a surgical emergency. Abdominal pain with weight loss, blood, or nocturnal symptoms needs further evaluation. A seizure with fever is not automatically a febrile seizure if the child is toxic or has meningeal signs.
Worked example
A 4-year-old has a soft grade 2/6 systolic murmur at the left upper sternal border that changes with position, no symptoms, and normal growth. This is likely an innocent murmur; no echocardiogram is required if the examination is otherwise normal. Rule of thumb: pathologic murmurs are diastolic, loud, harsh, click-associated, or symptomatic-those need imaging.