Hey there, future nurses! Are you preparing for the NCLEX and feeling a bit overwhelmed by all those lab values? Good news: the NCLEX gives you the reference ranges during the exam itself! So instead of memorizing numbers, you can spend more time focusing on the “why” or “how” during the exam.
Still, understanding lab values can help you spot issues before they become big problems and make you look like a rock star in front of your instructors and clients. That’s why we’ve put together an NCLEX lab values cheat sheet to help make lab values easier to digest before the NCLEX, and also set yourself up for success as a real-deal RN!
With easy-to-read normal ranges and some practical tips to remember them, you’ll be able to tackle any question or scenario that comes your way. So grab your favorite study snacks and let’s get into the world of lab values together, because who says studying can’t be a little enjoyable?
📘 Grab the Essential NCLEX Cheat Sheet!
Looking for a comprehensive NCLEX cheat sheet for vitals, conversions, key conditions, and more?
Download yours for FREE today!
The Most Common NCLEX Lab Values
Electrolytes
Sodium (Na)
- Normal: 136–145 mEq/L
- Critical: < 120 or > 160
- Why is this important? When we see imbalances in sodium we can expect to see effects to brain function, such as seizures, coma, or confusion. These changes are especially common in critical cases!
- Memory Tool: One salt packet costs $1.36 to $1.45
Potassium (K)
- Normal: 3.5–5.0 mEq/L
- Critical: < 2.5 or > 6.5
- Why is this important? Potassium plays a big role in the way our heart functions! Potassium that is too high (hyperkalemia) and potassium that is too low (hypokalemia) can cause life-threatening cardiac dysrhythmias.
- Memory Tool: “Bananas are $3.50 to $5.00 a bunch.”
- Bananas are high in potassium and will help students remember the range of 3.5-5.0.
Total Calcium (Ca)
- Normal: 9–10.5 mg/dL
- Critical: < 6.5 or > 13
- Why is this important? Imbalances in calcium can cause cardiac dysrhythmias, muscle spasms, and seizures.
- Memory Tool: 9–10.5 is the range you want for your bones to thrive!
Magnesium (Mg)
- 1.5–2.4 mg/dL
Chloride (Cl)
- 98–106 mEq/L
Phosphorous (PHOS)
- 3–4.5 mg/dL
Acid Base Balance
pH
- Normal: 7.35-7.45
- Critical: < 7.2 or > 7.6
- Why is it important? Extreme pH levels affect nearly all body functions and can lead to organ failure or respiratory/cardiovascular arrest.
PaCO2
- 35-45 mmHg
HCO3 (Bicarbonate)
- 22-26 mEq/L
PaO2
- 80-100 mmHg
SaO2 (O2 Saturation)
- 95-100%
Complete Blood Count (CBC)
White Blood Cells (WBC)
- 4,000–10,000/µL
Red Blood Cells (RBC)
- Men: 4.7–6.1 × 106/µL
- Women: 4.2–5.4 × 106/µL
Hemoglobin (Hgb)
- Men: 14–17 g/dL
- Women: 12–16 g/dL
Hematocrit (Hct)
- Men: 41%–51%
- Women: 36%–47%
Platelets
- 150,000–350,000/µL
Renal Function
Blood Urea Nitrogen (BUN)
- 8–20 mg/dL
Creatinine
- 0.7–1.3 mg/dL
Glomerular Filtration Rate (GFR)
- 90-120
- Varies based on age
Liver Function
AST
- 0–35 U/L
ALT
- 0–35 U/L
ALP
- Men: 45–115 U/L
- Women: 30–100 U/L
Bilirubin (Total)
- 0.3–1.2 mg/dL
Cardiac Markers
Troponin
- 0–0.5 ng/mL
CK-MB
- 0–7 ng/mL
Blood Glucose
- Fasting: 70-100 mg/dL
- Critical: < 50 or > 400
- Why is it important? Low blood glucose levels, or hypoglycemia, can lead to seizures or coma, while high blood glucose levels, or hyperglycemia, can cause diabetes-related ketoacidosis (DKA) or hyperglycemic hyperosmolar state (HHS).
- Memory Tool: When I’m between 70 and 100, I’m in the sweet spot!
HbA1c
- 4-6%
Coagulation
Prothrombin Time (PT)
- 11–13 sec
International Normalized Ratio (INR)
- 0.8–1.1
- Therapeutic Range for Warfarin: 2-3
- Memory Tool: “I’d like 2-3 wafers.” (“Wafers” sounds similar to “warfarin.”)
- Therapeutic Range for Warfarin: 2-3
- Critical: > 4.5
- Why is it important? High INR can indicate a risk of bleeding, while low levels increase the risk of clotting.
Activated Partial Thromboplastin Time (aPTT)
- 25-35 seconds
Lipid Panel
Total Cholesterol
- 150–199 mg/dL
Low-Density Lipoprotein (LDL)
- ≤ 130 mg/dL
High-Density Lipoprotein (HDL)
- ≥ 40 mg/dL
Triglycerides
- < 150 mg/dL
Tips for Remembering NCLEX Lab Values
1. Study similar labs together.
Group by function or system.
One of the easiest ways to tackle lab values is to group them by their function, or the body systems they relate to. For example:
Electrolytes
Create a study sheet for all the key electrolytes, including potassium, sodium, calcium, and magnesium. Compare their normal ranges, understand their functions, and know the signs and symptoms of imbalances.
For example, remember that hyperkalemia (high potassium) can lead to life-threatening cardiac dysrhythmias, while hyponatremia (low sodium) may cause neurological changes.
Complete Blood Count (CBC)
Gather all the components of a CBC: hemoglobin, hematocrit, white blood cells, and platelets. Study how these values provide insight into a client’s overall health, immune status, and ability to clot.
For example, a low hemoglobin level can indicate anemia, while a high white blood cell count can indicate infection.
Liver Function Tests (LFTs)
Group tests like AST, ALT, alkaline phosphatase, and bilirubin together. Understand how these tests assess liver function and what abnormal results may indicate, such as liver disease or bile duct obstruction.
2. Create visual aids.
Visual aids were so helpful for me in nursing school and definitely help content stick in your brain! Consider making flashcards or charts that display grouped lab values and don’t be afraid to use different colors. Color coding information is a great memory trick too—for example:
Red: Means critical values that require immediate attention.
Green: This denotes normal ranges.
Yellow: This indicates a borderline lab value and requires continued monitoring that’s not emergent.
3. Remember the NCLEX provides normal ranges!
FOCUS ON CRITICAL RANGES! NCLEX questions will be often centered around the abnormal and critical values.
4. Practice with NCLEX style questions.
Working through practice questions is a great way to prepare for the NCLEX! An easy way to do that is by checking out our NCLEX Qbank filled with 1,000 practice questions, written by nurses for nurses to help you study stress-free and walk into your exam feeling confident. (Note that many of our practice questions are on lab values!)
5. Create clinical scenarios.
Develop clinical scenarios where specific lab values play a critical role. For example, imagine you’re caring for a client with liver dysfunction. You can discuss the relevant liver function tests and how abnormal values would guide your nursing interventions.
By applying NCLEX lab values to real-life scenarios, you’ll deepen your understanding and improve your recall. Working through scenarios will help you pass your NCLEX and start working on the floor as a real-deal RN!
6. Stay consistent, and review regularly.
Lastly, consistency is key! Make it a habit to review lab values regularly, even after you feel confident about them so they stay fresh in your mind. This regular reinforcement will help you solidify your knowledge and make it easier to recall information not only during the NCLEX, but also throughout your career.
Further Reading
By grouping similar lab values and using these fun study strategies, you’ll make NCLEX prep less stressful and more enjoyable! Make good use of your NCLEX lab values cheat sheet—it can really help you on exam day. Happy studying, and remember you’ve got this!
Looking for even more (free) content to help you prep for the NCLEX? Check out these other posts on the Blueprint Nursing blog:
