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. (AU note: the real NCLEX-RN exam — the same written exam both tracks sit — uses these US units, so they're worth memorizing as shown. For quick cross-reference against AU lab reports: sodium and potassium are numerically identical in mmol/L; calcium 9–10.5 mg/dL ≈ 2.25–2.62 mmol/L; magnesium 1.5–2.5 mEq/L ≈ 0.75–1.25 mmol/L; glucose 70–100 mg/dL ≈ 3.9–5.6 mmol/L; hemoglobin ≈ ×10 for g/L; platelets and WBC ÷1,000 for ×10⁹/L.)