10 Normal Lab Values For Nursing School and The NextGen NCLEX

Cracking the Code: Normal Lab Values for Nursing School and the NextGen NCLEX

Normal Lab Values for Nursing School and the NextGen NCLEX Discussed In This Article

Blood Urea Nitrogen (BUN)

Normal Levels for Blood urea nitrogen (BUN):
7-20 mg/dL

Description of Blood urea nitrogen (BUN):
Blood urea nitrogen (BUN) measures the amount of urea in the blood. When protein is broken down ammonia is formed. Ammonia is converted to urea in the liver and is eventually excreted in the kidneys.

Indications for Blood urea nitrogen (BUN): 

What would cause increased levels of Blood urea nitrogen (BUN):

What would cause decreased levels of Blood urea nitrogen (BUN):

• Liver Failure
• Overhydration
• Inadequate Protein Intake
• Pregnancy

When would you need to order a Blood urea nitrogen (BUN) lab value test?

A Blood Urea Nitrogen (BUN) test is commonly used to evaluate kidney function and assess the levels of nitrogen waste products, specifically urea, in the blood. It measures the amount of nitrogen in the form of urea that is present in the blood.

Clinical situation where a BUN test may be needed:

Dehydration: In cases of dehydration, like fluid loss from vomiting, diarrhea, or excessive sweating, the BUN levels may rise. This is because as the body becomes dehydrated, there is less water content in the blood, leading to an increased concentration of urea.

Nursing Case Study: Dehydration in an Athlete

• Patient Profile:
  • Sarah is a 28-year-old professional runner.
  • Complaints of fatigue, dizziness, and decreased urine output.
  • History of intense training and inadequate fluid intake.
• Physical Examination:
  • Fatigue, pale appearance, dry mucous membranes.
• Laboratory Findings:
  • Hemoglobin: 13 g/dL
  • BUN: 25 mg/dL
  • Urinalysis: Concentrated urine (specific gravity: 1.030)
• Diagnosis:
  • Dehydration
• Treatment:
  • Rehydration with oral rehydration solutions, sports drinks, and water.
  • Monitor fluid intake and urine output.

Hematocrit (Hct)

Normal Levels of Hematocrit (Hct):

Male: 41 – 50%
Female: 36 – 44%

Description for Hematocrit (Hct):
Hematocrit (Hct) is the percentage of the blood that is made up of packed Red Blood Cells (RBCs). A hematocrit level of 40% indicates that there are 40 mL packed red blood cells in 100 mL of blood.

Indications for Hematocrit (Hct):

• Identify:
  • Anemia
  • Bleeding
  • Bleeding disorder
  • Fluid imbalances

What would cause increased levels of Hematocrit (Hct):

What would cause decreased levels of Hematocrit (Hct):

When would you need to order a Hematocrit (Hct) lab value test?

A Hematocrit (Hct) lab value test is ordered in various situations to assess the proportion of red blood cells (RBCs) in the total blood volume.

Clinical situation where a Hematocrit (Hct) lab value test:

• Diagnosis and Monitoring of Anemia: A Hematocrit (Hct) test is commonly used to diagnose and monitor different types of anemia, including iron deficiency anemia, vitamin deficiency anemia, and hemolytic anemia. A low Hct level indicates a decrease in RBC count, which can contribute to anemia.

Nursing Case Study:  Iron Deficiency Anemia

• Patient Profile:
  • John Davis, a 35-year-old male teacher.
  • Complaints of fatigue, weakness, shortness of breath, and difficulty concentrating.
  • History of a vegetarian diet.
• Laboratory Findings:
  • Hemoglobin: 10 g/dL
  • Hematocrit: 30%
  • MCV: 70 fL
  • Serum Iron: 25 μg/dL
  • TIBC: 400 μg/dL
• Diagnosis:
  • Iron Deficiency Anemia
• Treatment options:
  • Iron Supplementation
  • Dietary Changes
  • Vitamin C Intake
  • Blood Transfusion

Hemoglobin (Hbg)

Normal Levels for Hemoglobin (Hbg):

Male: 13.5 – 16.5 g/dL
Female: 12.0 – 15.0 g/dL

Description for Hemoglobin (Hbg):
Hemoglobin (Hbg), an iron-containing compound, is the main protein in Red Blood Cells (RBCs). It enables oxygen and carbon dioxide (CO2) to bind to RBCs for
transport throughout the body.

Indications for Hemoglobin (Hbg):

• Identify
  • Bleeding disorders
  • Anemia
  • Blood loss

What would cause increased levels of Hemoglobin (Hbg):

What would cause decreased levels of Hemoglobin (Hbg):

When would you need to order a Hemoglobin (Hbg) lab value test?

A Hemoglobin (Hb) lab value test is ordered in various situations to assess the amount of hemoglobin, a protein in red blood cells that carries oxygen, in the blood.

Clinical situations where a Hemoglobin (Hbg) lab value: 

• Diagnosis and monitoring of anemia
• Evaluation of blood loss
• Preoperative assessment
• Monitoring chronic conditions
• Screening and monitoring athletes

Nursing Case Study: Postoperative Assessment

• Patient Profile:
  • Michael is a 65-year-old male postoperative patient.
  • History of hypertension and coronary artery disease.
• Chief Complaint:
  • Postoperative follow-up after cardiac bypass surgery.
• Laboratory Findings::
  • Hemoglobin: 9 g/dL
  • Hematocrit: 27% 
• Diagnosis:
  • Postoperative anemia requiring further evaluation and management.
• Treatment:
  • Michael’s treatment plan involves addressing his anemia, which may include iron supplementation, erythropoietin-stimulating agents, or additional blood transfusions if necessary. Further follow-up and monitoring will be conducted to assess his response to treatment.

Potassium (K+)

Normal Levels for Potassium (K+):
3.5 – 5.0 mEq/L

Description of Potassium (K+):
Potassium (K+) is the most abundant intracellular cation and plays a vital role in the transmission of electrical impulses in cardiac and skeletal muscle. It plays a
role in acid-base equilibrium. In states of acidosis, hydrogen will enter the cell which will force potassium out of the cell. A 0.1 decrease in pH will cause a 0.5
increase in K+.

Indications for Potassium (K+):

What would cause increased levels of Potassium (K+):

What would cause decreased levels of Potassium (K+):

When would you need to order a Potassium (K+) lab value test?

A Potassium (K+) lab value test is ordered in various situations to assess the level of potassium in the blood. 

Clinical situations where a  Potassium (K+) test may be needed:

• Evaluation of Electrolyte Balance
• Kidney Disease
• Cardiac Conditions
• Electrolyte Imbalance Symptoms

Nursing Case Study: Electrolyte Imbalance Symptoms

• Patient Profile:
  • Name: Sarah 
  • Age: 45
  • Occupation: Office Administrator
  • Medical History: Hypertension, Type 2 Diabetes
• Chief Complaint:
  • Sarah Johnson presents to the emergency department with complaints of muscle weakness, fatigue, and irregular heartbeat. She reports feeling generally unwell and experiencing occasional numbness and tingling in her extremities.
• Laboratory Findings:
  • Hemoglobin, Hematocrit, and Red Blood Cell count within normal range.
  • Potassium: 2.8 mmol/L
  • Sodium, Calcium, and Magnesium levels within normal range.
• Diagnosis:
  • Hypokalemia (low potassium levels) causing electrolyte imbalance.
• Treatment:
  • Sarah’s treatment plan involves correcting her electrolyte imbalance by addressing the underlying cause of hypokalemia. Intravenous potassium supplementation is initiated to raise her potassium levels to the appropriate range. Close monitoring of her electrolytes and cardiac function is maintained during the treatment.

Sodium (Na+)

Normal Levels for Sodium (Na+):
135-145 mEq/L

Description of Sodium (Na+):
Sodium (Na+) is the most abundant cation in extracellular fluid. Sodium aids in osmotic pressure, renal retention and excretion of water, acid-base balance, and regulation of other cations and anions in the body. Sodium plays a role in blood pressure regulation and stimulation of neuromuscular reactions. Sodium and water have a direct relationship; water follows salt.

Indications for Sodium (Na+):

• Monitor
  • Extracellular osmolality
  • Electrolyte imbalance

What would cause increased levels of Sodium (Na+):

What would cause decreased levels for Sodium (Na+):

When would you need to order a Sodium (Na+) lab value test?

A Sodium (Na+) lab value test is ordered in various situations to assess the level of sodium in the blood. Here are some scenarios where a Sodium test, along with metabolic acidosis

Clinical situations where a Sodium (Na+) lab test may be needed:

• Evaluation of Electrolyte Balance: Sodium is a crucial electrolyte that helps maintain fluid balance, nerve function, and acid-base balance in the body. Metabolic acidosis, a condition characterized by an imbalance in the body’s acid-base equilibrium, can disrupt sodium levels.
• Assessment of Acid-Base Disorders: Metabolic acidosis occurs when there is an excess of acid or a decrease in the bicarbonate levels in the blood. This can be caused by conditions such as diabetic ketoacidosis, kidney dysfunction, or severe diarrhea.

Nursing Case Study: Metabolic Acidosis

• Patient Profile:
  • Name: John
  • Age: 35
  • Medical History: Type 2 diabetes, Chronic Kidney Disease (Stage 3)

• Chief Complaint:
  • John is admitted to the hospital with complaints of deep and rapid breathing, generalized weakness, and confusion. He mentions feeling extremely fatigued and experiencing nausea over the past few days.
• Laboratory Findings:
  • pH: 7.28
  • Bicarbonate (HCO3-): 16 mmol/L 
  • Sodium (Na+): 138 mEq/L 
  • Potassium (K+): 4.2 mEq/L
• Diagnosis:
  • Metabolic acidosis secondary to diabetic ketoacidosis (DKA) and dehydration.

• Treatment:
  • Fluid Resuscitation
  • Insulin Therapy
  • Electrolyte Monitoring: Regularly assess and monitor sodium, potassium, and bicarbonate levels to guide treatment and ensure appropriate electrolyte balance.

Creatinine (Cr)

Normal Levels for Creatinine (Cr):
0.7-1.4 mg/dL

Description of Creatinine (Cr):
Creatinine (Cr) is a byproduct of creatine metabolism, and it is excreted by the kidneys. Creatinine is created in proportion to muscle mass and usually stays stable.

Indications for Creatinine (Cr):

• Identify
  • Muscular disorders
  • Renal disease

What would cause increased levels of Creatinine (Cr):

What would cause decreased levels of Creatinine (Cr):

When would you need to order a Creatinine (Cr) lab value test?

A Creatinine (Cr) lab value test is ordered in various situations to assess kidney function and monitor renal health. 

Clinical situations where a Creatinine (Cr) lab test may be needed:

• Evaluation of Kidney Function
• Monitoring Chronic Kidney Disease (CKD)
• Evaluation of Acute Kidney Injury (AKI)

Nursing Case Study: Evaluating Kidney Function

• Patient Profile:
  • Name: Emily
  • Age: 68
  • Medical History: Hypertension, Diabetes Mellitus Type 2, Chronic Kidney Disease (Stage 3)

• Chief Complaint:
  • Emily visits her primary care physician with complaints of increased fatigue, decreased urine output, and swelling in her lower extremities over the past few weeks.
• Laboratory Findings:
  • Creatinine: 2.2 mg/dL
  • BUN: 40 mg/dL
  • Sodium, Potassium, and Calcium levels within the normal range

• Diagnosis:
  • Impaired kidney function and worsening chronic kidney disease.
• Treatment:
  • Medication Adjustment
  • Dietary Modifications
  • Fluid Management
  • Blood Pressure Management

International Normalized Ratio (INR)

Normal Levels for International normalized ratio(INR):
0.8 – 1.2
Therapeutic Levels of Warfarin 2.0 – 3.5

Description of International normalized ratio(INR):
International normalized ratio(INR) takes results from a prothrombin time test and standardizes it regardless of the collection method.

Indications for International normalized ratio(INR):

• Evaluate therapeutic doses of Warfarin
• Identify patients at higher risk for bleeding
• Identify cause of
  • Bleeding
  • Deficiencies

What would cause increased levels in International normalized ratio(INR):

• Disseminated Intravascular Coagulation (DIC)
• Liver disease
• Vitamin K deficiency
• Warfarin

What would cause decreased levels in International normalized ratio(INR):

• Too much vitamin K
• Estrogen-containing medications such as birth control

When would you need to order an International normalized ratio(INR) lab value test?

An International Normalized Ratio (INR) lab value test is ordered in various situations to monitor and assess blood clotting function, particularly when individuals are on anticoagulant therapy.

Clinical situations where an International normalized ratio(INR) lab test may be needed:

• Monitoring Warfarin Therapy
• Dose Adjustment of Anticoagulants
• Evaluation of Liver Function
• Monitoring Coagulation Disorders
• Assessment of Bleeding Disorders
• Preoperative Assessment

Nursing Case Study: Monitoring Warfarin Therapy

• Patient Profile:
  • Name: Stacy
  • Age: 60
  • Medical History: Atrial Fibrillation, Deep Vein Thrombosis (DVT)

• Chief Complaint:
  • Stacy presents to the anticoagulation clinic for a routine follow-up appointment. She reports feeling well and has no specific complaints.
• Laboratory Findings:
  • INR: 2.5 (Target range: 2.0-3.0)
• Diagnosis:
  • INR within the target range, indicating the therapeutic effectiveness of warfarin therapy in preventing excessive blood clotting.
• Treatment:
  • Medication Adherence: Reinforce the importance of medication adherence and consistent dosing of warfarin.
  • Education on Bleeding Precautions
  • Follow-up Schedule
  • Assessing Adverse Effects: Monitor Stacy for signs of medication-related adverse effects, such as signs of bleeding or signs of overdose

Calcium (Ca2+)

Normal Levels for Calcium (Ca+):
8.4-10.2 mg/dL

Description of Calcium (Ca+):
Calcium (Ca+), a positive ion in the body, is necessary for neuromuscular processes, bone mineralization, and hormonal secretion. The parathyroid gland and vitamin
D is responsible for calcium regulation in the body. In the blood, about half of calcium travels in ion form, the other half is bound to proteins like albumin. When
albumin levels are low, calcium levels will appear lower. Calcium has an important relationship with phosphorus: they are inversely proportional.

Indications for Calcium (Ca+):

• Identify problems with
  • Parathyroid
  • Neuromuscular functions
  • Diseases that affect bone
  • Effectiveness of treatments

What would cause increased levels in Calcium (Ca+):

What would cause decreased levels of Calcium (Ca+):

When would you need to order a Calcium (Ca+) lab value test?

A Calcium (Ca+) lab value test may be ordered in various situations to assess calcium levels in the blood. Here are some common scenarios where a Calcium lab value test may be needed:

Clinical situations where calcium (Ca+) lab test may be needed:

• Evaluation of Calcium Disorders
• Monitoring Parathyroid Function
• Assessment of Kidney Function
• Evaluation of Bone Health
• Monitoring Calcium Therapy
• Assessment of Malabsorption or Malnutrition
• Evaluation of Cardiac Function

Nursing Case Study: Evaluation of Hypocalcemia

• Patient Profile:
  • Name: Abby
  • Age: 40
  • Medical History: Chronic Kidney Disease, Vitamin D Deficiency

• Chief Complaint:
  • Abby presents to the emergency department with complaints of muscle cramps, tingling sensations in his hands and feet, and a recent history of fatigue and weakness.
• Laboratory Findings:
  • Calcium: 7.8 mg/dL
• Diagnosis:
  • Hypocalcemia (low calcium levels) secondary to chronic kidney disease and impaired calcium regulation.
• Treatment:
  • Intravenous Calcium Administration
  • Vitamin D Supplementation
  • Ongoing Monitoring
  • Symptom Management: Implement measures to relieve muscle cramps and tingling sensations

Red Blood Cell (RBC)

Normal Levels for Red Blood Cells (RBCs):
Male: 4.5 – 5.5 x106/cells/mm3
Female: 4.0 – 4.9 x106/cells/mm3

Description of Red Blood Cells (RBCs):
Red Blood Cells (RBCs) contain hemoglobin which is responsible for oxygen transport throughout the body. RBCs are primarily produced in the bone marrow, they
have a lifespan of 120 days and are destroyed in the spleen and liver. RBC production is regulated by erythropoietin (EPO), which is produced and released from
the kidneys.

Indications for Red Blood Cells (RBCs):

• Identify
  • Anemia
  • Blood loss

What would cause increased levels in Red Blood Cells (RBCs):

What would cause decreased levels in Red Blood Cells (RBCs):

When would you need to order a Red Blood Cells (RBCs) lab value test?

A Red Blood Cells (RBCs) lab value test may be ordered in various situations to assess the number and characteristics of red blood cells in the blood. 

Clinical situations where Red Blood Cells (RBCs) lab test may be needed:

• Evaluation of Anemia
• Monitoring Chronic Conditions: Individuals with chronic conditions that can affect red blood cell production or survival may require regular RBC testing
  • chronic kidney disease
  • liver disease
  • bone marrow disorders
• Evaluation of Blood Loss
• Diagnosis of Polycythemia
• Preoperative Evaluation

Nursing Case Study: Anemia

• Patient Profile:
  • Name: Kelly
  • Age: 28
  • Medical History: History of gastric ulcers, gastrointestinal bleeding

• Chief Complaint:
  • Kelly presents to the emergency department with complaints of persistent fatigue, weakness, and shortness of breath upon exertion.
• Laboratory Findings:
  • Hemoglobin: 9.0 g/dL
  • RBC Count: 3.6 million cells/mcL 
• Diagnosis:
  • Anemia, likely caused by menorrhagia (excessive menstrual bleeding).
• Treatment:
  • Iron Supplementation
  • Menstrual Management
  • Symptom Management
  • Follow-up Care

Thyroid Stimulating Hormone (TSH)

Normal Levels for Thyroid Stimulating Hormone (TSH)
2-10 mU/L

Indications for Thyroid Stimulating Hormone (TSH)

• Diagnose:
  • Hyperthyroidism
  • Hypothyroidism
•  Monitor thyroid replacement therapy

Description of Thyroid Stimulating Hormone (TSH)

Thyroid Stimulating Hormone (TSH) is released from the pituitary in response to
low levels of thyroid hormone. TSH communicates to the thyroid gland to release
the thyroid hormones Triiodothyronine (T3) and Thyroxine (T4). Thyroid hormones
regulate metabolism. T3 and T4 have an inverse relationship with TSH.

What would cause increased levels of Thyroid Stimulating Hormone (TSH)?

What would cause decreased levels of Thyroid Stimulating Hormone (TSH)?

When would you need to order a Thyroid Stimulating Hormone (TSH) lab value test?

A Red Blood Cells (RBCs) lab value test may be ordered in various situations to assess the number and characteristics of red blood cells in the blood. 

Clinical situations where Thyroid Stimulating Hormone (TSH) lab test may be needed:

• Suspected Thyroid Dysfunction
• Monitoring Thyroid Replacement Therapy
• Evaluation of GoiterUnexplained Symptoms:

Nursing Case Study: Hypothyroidism

• Patient Profile:
  • Name: Emily
  • Age: 38
  • Medical History: None reported

• Chief Complaint:
  • Emily Roberts presents to the primary care clinic with complaints of weight gain, fatigue, and cold intolerance.
• Laboratory Findings:
  • TSH: 8.5 mIU/L
  • Free T4: 0.8 ng/dL
• Diagnosis:
  • Hypothyroidism, characterized by an elevated TSH level and decreased free T4 level.
• Treatment:
  • Levothyroxine Replacement Therapy
  • Symptom Management
  • Regular Follow-up
  • Patient Education

Conquer the NextGen NCLEX

Understanding nursing lab values can give you a significant advantage in conquering the NextGen NCLEX. The Next Generation NCLEX (NextGen NCLEX) is an updated version of the NCLEX-RN examination that aims to assess nursing students’ clinical judgment skills and their ability to provide safe and effective patient care.

Lab values play a crucial role in the assessment, monitoring, and management of patients across various healthcare settings. By having a solid understanding of normal lab values and their significance you can enhance your critical thinking.

Lab values challenge your critical thinking skills by requiring you to analyze and interpret data within the context of a patient’s overall health. The NextGen NCLEX is designed to assess your ability to analyze complex patient scenarios and lab values are often integrated into these scenarios. By grasping the nuances of lab values, you can better evaluate patient conditions and make informed decisions.

Understanding Normal Lab Values is an Essential Component of Nursing School Education

In conclusion, understanding normal lab values is an essential component of nursing school education. These values provide crucial insights into a patient’s health status, aiding in diagnosis, treatment planning, and monitoring of various conditions. By familiarizing yourself with the normal ranges and interpreting lab results effectively, you’ll be equipped to provide comprehensive and competent care to your patients.

Remember, lab values should be considered in conjunction with the patient’s clinical presentation, medical history, and other diagnostic findings. As a nurse, it is our responsibility to communicate effectively with the healthcare team, interpret lab values accurately, and advocate for the best possible care for our patients.

By mastering the understanding of normal lab values, you will strengthen your ability to ADPIE effectively. 

You CAN do this.

Happy Nursing!