Vital Signs, Lab Values & Diagnostic Tests

Memorize normal adult ranges cold, since dozens of questions hinge on recognizing an abnormal value: sodium 135–145 mEq/L, potassium 3.5–5.0 mEq/L, calcium 9–10.5 mg/dL, magnesium 1.5–2.5 mEq/L, glucose (fasting) 70–100 mg/dL, hemoglobin roughly 12–16 g/dL (female) / 14–18 g/dL (male), platelets 150,000–400,000/mm³, white blood cells 5,000–10,000/mm³, and INR 0.8–1.1 in a patient not on anticoagulation.