NCLEX Lab Values - Complete Reference Guide for 2025
Lab Values Overview
Basic Metabolic Panel (BMP) Na 135-145, K 3.5-5.0, Cl 98-106, HCO₃ 22-28, BUN 7-20, Cr 0.6-1.2, Glucose 70-110
Complete Blood Count (CBC) WBC 4-11k, Hgb 12-18, Hct 36-48%, Plt 150-400k
Coagulation Studies PT 11-14, INR 0.8-1.1 (2-3 therapeutic), aPTT 30-40, D-dimer <0.5< /td>
Cardiac Enzymes Troponin I <0.04, CK-MB <5, BNP <100
Liver Function Tests AST 10-40, ALT 10-40, Total bili 0.1-1.2
Arterial Blood Gases (ABGs) pH 7.35-7.45, PaCO₂ 35-45, HCO₃ 22-26, PaO₂ 80-100, O₂ sat 95-100%

NCLEX Lab Values: Complete Reference Guide for 2025

Understanding NCLEX lab values is one of the most important skills for nursing students preparing for the exam. The NCLEX frequently tests your ability to interpret lab results, identify emergencies, and make safe clinical decisions. This updated 2025 NCLEX lab values guide provides all essential ranges you must memorize to succeed.

  • BMP
  • CBC
  • Cardiac
  • LFTs
  • ABGs
lab values 2025

Why Lab Values Matter for NCLEX

Lab values help nurses determine a patient's status quickly. On NCLEX, abnormal values often indicate life‑threatening situations requiring immediate intervention. These values appear in NGN case studies, bow‑tie items, matrix questions, and prioritization scenarios. Mastering normal lab ranges is key to answering these questions with confidence.

Basic Metabolic Panel (BMP)

These labs assess kidney function, hydration status, and electrolyte balance:

BMP Normal Ranges
  • Sodium (Na): 135–145 mEq/L
  • Potassium (K): 3.5–5.0 mEq/L
  • Chloride (Cl): 98–106 mEq/L
  • Bicarbonate (HCO₃): 22–28 mEq/L
  • BUN: 7–20 mg/dL
  • Creatinine: 0.6–1.2 mg/dL
  • Glucose: 70–110 mg/dL

Complete Blood Count (CBC)

These values help identify infection, oxygenation issues, and bleeding risk:

CBC Normal Ranges
  • WBC: 4,000–11,000 /mm³
  • Hemoglobin: 12–16 g/dL (female), 14–18 g/dL (male)
  • Hematocrit: 36–48%
  • Platelets: 150,000–400,000 /mm³

Coagulation Studies

These determine clotting ability and bleeding risk:

Coag Normal Ranges
  • PT: 11–14 seconds
  • INR: 0.8–1.1 (therapeutic: 2–3 for warfarin)
  • aPTT: 30–40 seconds
  • D‑dimer: < 0.5 µg/mL

Cardiac Enzymes

These labs indicate heart damage or failure:

Cardiac Normal Ranges
  • Troponin I: < 0.04 ng/mL
  • CK‑MB: < 5 ng/mL
  • BNP: < 100 pg/mL

Liver Function Tests (LFTs)

LFTs Normal Ranges
  • AST: 10–40 U/L
  • ALT: 10–40 U/L
  • Total bilirubin: 0.1–1.2 mg/dL

Arterial Blood Gases (ABGs)

These assess respiratory and metabolic balance:

ABGs Normal Ranges
  • pH: 7.35–7.45
  • PaCO₂: 35–45 mmHg
  • HCO₃: 22–26 mEq/L
  • PaO₂: 80–100 mmHg
  • O₂ saturation: 95–100%
Category Lab Test Normal Range Clinical Significance
BMP Sodium 135-145 Fluid balance, neuro status
Potassium 3.5-5.0 Cardiac rhythm, muscle function
BUN 7-20 Kidney function, hydration
Creatinine 0.6-1.2 Kidney function
Glucose 70-110 Diabetes, stress response
WBC 4-11k Infection, inflammation
Hgb 12-18 Anemia, oxygenation
Coag INR 0.8-1.1 (therapeutic 2-3) Anticoagulation therapy
Cardiac Troponin <0.04 Myocardial infarction
ABG pH 7.35-7.45 Acid-base balance

Tips for Studying Nursing Lab Values

  • Group labs by system for easier memorization.
  • Use flashcards daily for repetition.
  • Associate abnormal values with symptoms.
  • Practice NCLEX-style lab interpretation questions.
  • Create mnemonic devices for hard-to-remember ranges.
  • Focus on high-yield values: K+, Na+, Glucose, Troponin, INR.
Memory Tricks
  • Potassium (3.5-5.0): "3.5 to 5.0 keeps the heart alive"
  • Calcium (8.5-10.5): "8.5 to 10.5 keeps bones alive"
  • INR (2-3 therapeutic): "2 to 3 for Coumadin therapy"

Lab Values Mastery Checklist

BMP: Na, K, BUN, Cr, Glucose
CBC: WBC, Hgb, Hct, Plt
Coag: PT, INR, aPTT
Cardiac: Troponin, CK-MB, BNP
LFTs: AST, ALT, Bilirubin
ABGs: pH, PaCO₂, HCO₃, PaO₂
Know critical values
Associate with symptoms

Final Thoughts

Mastering these nursing lab values is essential for NCLEX success. With this complete 2025 reference guide, you'll confidently recognize abnormal results, prioritize care, and handle NGN clinical judgment questions with ease.

key takeaway

Memorize essential NCLEX lab values: BMP (Na, K, BUN, Cr, glucose), CBC (WBC, Hgb, Plt), Coag (INR), Cardiac (Troponin), ABGs (pH, PaCO₂, HCO₃)-associate abnormalities with symptoms.