Lab Values Nursing Students Need to Know for NCLEX

Knowing what to focus on for the NCLEX can be difficult, especially when it comes to lab values. Some lab values are more common than others. This guide will cover the lab values nursing students need to know to pass the NCLEX.

Common NCLEX Nursing Lab Values

It’s important to understand the normal range for the lab values and the reason why a medical provider would order them.  Here are the common normal lab values you’ll need to know.

Complete Blood Count

A complete blood count (CBC) measures five key components including, 

  • Red Blood Cell: Cells that carry oxygen
  • White Blood Cell: Cells that fight infection
  • Hemoglobin: Oxygen-carrying protein in red blood cells
  • Hematocrit: Proportion of red blood cells to the fluid component, or plasma, in blood
  • Platelets: Help with blood clotting

What is a CBC Used For?

A CBC can be used to identify infections, anemia, autoimmune disorders, bone marrow disorders, thrombocytopenia, erythrocytosis, and different types of cancer, including leukemia. 

When to Order a CBC

A healthcare provider may order a CBC if a patient has, 

  • Bruising
  • Bleeding
  • Fatigue
  • Dizziness
  • Weakness
  • Inflammation
  • Joint pain
  • Blood pressure concerns
  • Heart issues

Normal CBC Levels

  • WBC: 4,500 to 11,000
  • Hemoglobin: 11 to 18 g/dL
  • Hematocrit: Women 36-44%, Men 41-50%
  • Platelets: 150,000 to 450,000

Metabolic Panel

According to the National Library of Medicine, a metabolic panel is a  group of blood tests that provides information about your body’s metabolism. There are two panels that  are commonly referred to as a metabolic panel,

  • Basic Metabolic Panel (BMP)
  • Complete Metabolic Panel (CMP)

BMP Normal Lab Values

Normal lab findings for a BMP are, 

  • BUN: 6 to 20 mg/dL
  • CO2 (carbon dioxide): 23 to 29 mmol/L
  • Creatinine: 0.8 to 1.2 mg/dL
  • Glucose: 64 to 100 mg/dL
  • Chloride: 96 to 106 mmol/L
  • Potassium: 3.7 to 5.2 mEq/L
  • Sodium: 136 to 144 mEq/L
  • Calcium: 8.5 to 10.2 mg/dL

CMP Normal Lab Values

A CMP measures all of the above and, 

  • ALP: 44 to 147 (IU/L)
  • AST: 8 to 33 U/L
  • ALT: 4 to 36 U/L
  • Bilirubin: 0.1 to 1.2 mg/dL
  • Total Protein: 6.0 to 8.3 g/dL
  • Albumin: 3.4 to 5.4 g/dL
  • Globulin: 2.0 to 3.5 g/dL

What is a Metabolic Panel Used For?

This is a very common blood test that is run for a variety of reasons, but generally – most hospitalized patients will have this test ordered. This lab can be used to check for medical conditions such as diabetes, high blood pressure, and kidney disease. 

Arterial Blood Gas

An arterial blood gases (ABG) test is a blood test that measures the acidity, or pH, and the levels of oxygen (O2) and carbon dioxide (CO2) from an artery. 

The test is used to check the function of the patient’s lungs and how well they are able to move oxygen into the blood and remove carbon dioxide.  

ABG Components

There are six key components to an ABG. They include,

  1. pH – This measures the balance of acids and bases in your blood.
  2. Partial pressure of oxygen (PaO2) – This measures the pressure of oxygen dissolved in your blood.
  3. Partial pressure of carbon dioxide (PaCO2) – This measures the amount of carbon dioxide in your blood and how well carbon dioxide can move out of your body.
  4. Bicarbonate (HCO3) – This is calculated using the measured values of pH and PaCO2 to determine the amount of the basic compound made from carbon dioxide (CO2.)
  5. Oxygen saturation (O2 Sat) – This measures how much hemoglobin in your blood is carrying oxygen.
  6. Oxygen content (O2CT) – This measures the amount of oxygen in your blood.
  7. Hemoglobin – This measures the amount of hemoglobin in your blood.

ABG Normal Values

The aforementioned components all have different normal values and represent different aspects of the blood gas. According to the National Institute of Health, typical normal values are:

  • pH: 7.35-7.45
  • Partial pressure of oxygen (PaO2): 75 to 100 mmHg
  • Partial pressure of carbon dioxide (PaCO2): 35-45 mmHg
  • Bicarbonate (HCO3): 22-26 mEq/L
  • Oxygen saturation (O2 Sat): 94-100%

When to Order an ABG

A medical provider may order an ABG for a variety of reasons including but not limited to, lung failure, sepsis, pneumonia, hypovolemic shock, trauma, asthma, drug overdose, heart failure, and emphysema.

Coagulation Level

Coagulation levels refer to several labs including,

  • Activated partial thromboplastin time (PTT)
  • Prothrombin time (PT)
  • Thrombin time (TT)
  • Fibrinogen
  • INR

When to Run Coagulation Levels

Some common reasons a medical provider may run coagulation levels is concern for liver disease, vitamin K deficiency, if a patient is on blood-thinning medication, and heart disease/problem. Labs may be ordered if a patient is suffering from, 

  • Bleeding
  • Easy bruising
  • Swelling
  • Pain
  • Stiffness
  • Blood clots

Normal Coagulation Levels

Normal levels for coagulation tests include, 

  • PTT: 25 to 35 seconds
  • PT: 11 to 13.5 seconds
  • TT: 14 to 19 seconds
  • Fibrinogen: 200 to 400 mg/dL
  • INR: 1.1 or below 

Lipid Panel

A lipid panel is also referred to as a cholesterol panel or fasting lipid panel or non-fasting lipid panel.

  • Total Cholesterol: Overall cholesterol level — the combination of LDL, VLDL and HDL.
  • Low-density lipoprotein (LDL): Referred to as “bad cholesterol” collects in blood vessels and is the main source of cholesterol buildup and blockage in the arteries
  • Very low-density (VLDL) lipoprotein: Total cholesterol minus your HDL
  • High-density (HDL) lipoprotein: Referred to as “good cholesterol” helps decrease the buildup of LDL in your blood vessels.
  • Triglycerides (TG): Type of fat in the blood

Normal Lipid Panel Values

According to Johns Hopkins Medicine, typical normal values are:

  • Total cholesterol: Less than 200 mg/dL
  • LDL: Less than 100 mg/dL
  • VLDL: Between 2 and 30 mg/dL
  • HDL: 45 to 70 mg/dL for men, 50 to 90 mg/dL for women.
  • Triglycerides: Less than 150 mg/dL

Hemoglobin A1C

An A1C level measures average blood sugar levels over the past 3 months. The A1C test is also called the glycated hemoglobin, glycosylated hemoglobin, hemoglobin A1C or HbA1c test. 

When to Order an A1C Test

This lab test is used to help diagnose prediabetes and diabetes as well as manage patients already diagnosed with diabetes. 

A1C Values 

  • Normal: Below 5.7%
  • Prediabetes: 5.7% to 6.4%
  • Diabetes: 6.5% or more

Drug Levels

Some medications have therapeutic blood levels. This is important so that medical providers can safely titrate medication doses so that patients are receiving the proper amount of a medication. 

When to Order Drug Levels

Healthcare providers will routinely order drug levels until a safe level is obtained. 

Normal Drug Level Lab Values

The most common drug levels are, 

  • Digoxin: 0.5-2 ng/mL
  • Carbamazepine: 4-10 mcg/mL
  • Dilantin: 10-20 mcg/mL
  • Theophylline: 10-20 mcg/mL
  • Phenobarbital: 15-40 mcg/mL
  • Lithium: 0.5-1.2 mmol/L
  • Valproic Acid: 50-100 mcg/mL

What You’re Likely to be Asked About on the NCLEX

The NCLEX will never ask a straight question about lab values asking you to pick the normal or abnormal range. Instead, the question may focus on problems, signs, and/or symptoms a patient may be experiencing. 

NCLEX Example Question 1

For example, a question might indicate a patient is suffering from the following signs and symptoms,

  • Fruity-smelling breath
  • Nausea and vomiting
  • Shortness of breath
  • Dry mouth
  • Weakness
  • Confusion
  • Abdominal pain

These are all signs of hyperglycemia or TOO HIGH blood sugar levels. The question might ask you to indicate which commonly ordered blood test should be drawn. In turn, you must know that the patient needs their glucose level checked and glucose is part of a Metabolic Panel.

NCLEX Example Question 2

Another example of a question that would be asked on the NCLEX regarding lab values is about a patient with an elevated WBC. A question may indicate that the patient’s WBC is 350,000 and the patient is also experiencing sudden, unintentional weight loss, bruising, recurrent nosebleeds, and swollen lymph nodes.

First, you will have to determine if the WBC is elevated or below the normal range. A normal range for a WBC is 4,500 to 11,000. Knowing the normal range will indicate that the WBC of 350,000 is extremely elevated and coupled with the signs and symptoms, this patient may be diagnosed with leukemia.

Why You Need to Know These Lab Values

All labs for nurses are important but the labs included above are the most commonly ordered labs. 

While it is important to understand and know these labs for the NCLEX, it is also extremely important to know these labs for your future nursing career. 

Understanding the normal and abnormal ranges for these labs is essential to providing the best care possible for your patients. 

The Best Way to Prepare for Lab Values Questions on the NCLEX

There are several key ways to prepare for questions involving lab values on the NCLEX.

  1. Incorporate lab value questions into your normal study routine. While the questions asked on the NCLEX will not specifically be “What is the normal range for a Calcium level of a patient?” it is important to understand normal values to identify key signs and symptoms of hypo or hyper concerns.
  2. Practice, Practice, Practice!
  3. Understand how the test works and how much time you have so you are not caught off guard during the exam
  4. Work in study groups and practice explaining your studies out loud to help you remember
  5. Take practice exams
  6. Take study breaks
  7. Use online or in-person NCLEX review course
  8. Establish an NCLEX study routine

*This website is provided for educational and informational purposes only and does not constitute providing medical advice or professional services. The information provided should not be used for diagnosing or treating a health problem or disease.


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