NCSBN distributes NCLEX-RN questions across 4 major categories with 8 subcategories
Ensures nurses protect clients and manage care safely across all settings.
The largest category. Tests physiological care across basic needs, pharmacology, risk reduction, and adaptation.
Disease prevention, growth and development across the lifespan, and health education.
Mental health, behavioral disorders, coping, and end-of-life care. Therapeutic communication is heavily tested.
| Lab | Normal range | Critical low | Critical high | Key clinical significance |
|---|---|---|---|---|
| Na⁺ (Sodium) | 136–145 mEq/L | <120 | >160 | Fluid balance, neurological status |
| K⁺ (Potassium) | 3.5–5.0 mEq/L | <2.5 | >6.5 | Cardiac rhythm — most commonly tested |
| Ca²⁺ (Calcium) | 8.5–10.5 mg/dL | <7.0 | >13.0 | Neuromuscular, cardiac, bone |
| Glucose | 70–100 mg/dL (fasting) | <40 | >500 | Hypoglycemia s/s: confusion, diaphoresis |
| HgB (Hemoglobin) | M: 14–18 · F: 12–16 g/dL | <7 | — | Oxygen carrying capacity, anemia |
| WBC | 5,000–10,000 /mm³ | <2,000 | >30,000 | Infection, immunocompromise |
| Platelets | 150,000–400,000 /mm³ | <50,000 | >1,000,000 | Bleeding risk below 50,000 |
| INR | 0.8–1.1 (therapeutic 2–3) | — | >4 | Warfarin monitoring — antidote: Vit K |
| pH (arterial) | 7.35–7.45 | <7.20 | >7.60 | Acid-base balance — <7.35 = acidosis |
| PaO₂ | 80–100 mmHg | <60 | — | O₂ supplementation below 60 |
| Creatinine | 0.6–1.2 mg/dL | — | >10 | Kidney function — rising = renal failure |
| BUN | 10–20 mg/dL | — | >100 | Renal function, hydration status |