NCLEX Review: Lab Values For Nurses and Nursing Students

Lab values, also known as reference ranges or normal ranges, are the values that are considered normal for a particular laboratory test. These values are typically based on the results of a large group of healthy individuals and are used to interpret the results of laboratory tests. It is important to note that lab values can vary depending on the laboratory that is performing the test, as well as other factors such as age, sex, and certain medications.

Here is a list of some common lab values and their meanings:

• Hemoglobin: This is a protein in red blood cells that carries oxygen to the body’s tissues. Normal values for adult males are generally between 13.5 and 17.5 grams per deciliter (g/dL), and for adult females, they are generally between 12.0 and 15.5 g/dL.
• White blood cell count (WBC): This is a measure of the number of white blood cells in the blood. Normal values for WBC are generally between 4,500 and 10,000 cells per microliter (cells/μL).
• Platelets: These are small cells in the blood that help with clotting. Normal values for platelets are generally between 150,000 and 450,000 cells per microliter (cells/μL).
• Sodium: This is an electrolyte that helps maintain the balance of fluids in the body. Normal values for sodium are generally between 135 and 145 milliequivalents per liter (mEq/L).
• Potassium: This is another electrolyte that helps maintain the balance of fluids in the body. Normal values for potassium are generally between 3.5 and 5.0 mEq/L.
• Cholesterol: This is a type of fat found in the blood. Normal values for total cholesterol are generally less than 200 milligrams per deciliter (mg/dL).
• Blood glucose: Blood glucose is a measure of the amount of sugar in the blood. Normal values for blood glucose in adults are typically between 70-100 mg/dL.

It is important to discuss any abnormal lab values with a healthcare provider, as they can indicate the presence of a medical condition that requires further evaluation and treatment.

The following list is a sampling of common lab values generally considered normal:

Blood Gases

• pH: 7.35-7.45
• PaO2: 80-100 mm Hg
• PaCO2: 35-45 mm Hg
• HCO3: 22-26 mEq/L
• SaO2: >95%

Total Cholesterol

• <200 mg/dL

HDL

• Females: 35-80 mg/dL
• Males: 35-65 mg/dL

LDL

• <130 mg/dL

Triglycerides

• <150 mg/dL

WBC

•  5,000 – 10,000/uL

Platelets

• 150,000 – 400,000 mm3

Hemoglobin

• Females: 12-16 g/dL
• Males: 14-18 g/dL

Hematocrit

• Females: 37-47%
• Males:  42-52%

PT

• 11-12.5 seconds (therapeutic—for someone on warfarin is 1.5-2.5 times the normal range—-16-31 seconds)

aPTT

• 30-40 seconds (therapeutic—for someone on Heparin is 1.5-2 times the normal range—–45-80 seconds)

INR

• 2-3 (therapeutic range for someone on warfarin). Someone not on warfarin:  0.8-1.1

D-dimer

• 0-250 ng/mL (may also be reported as Positive or Negative)

Fibrinogen Levels

• 170-340 mg/dL

Fibrin Degradation Products

•  <10 mcg/mL

Sodium

• 135-145 mEq/L

Potassium

• 3.5-5 mEq/L

Chloride

• 98-106 mEq/L

Calcium

• 9-10.5 mg/dL

Magnesium

• 1.3-2.1 mEq/L (therapeutic range—for someone on magnesium for preeclampsia—– 4-7mEq/L)

Phosphorus

• 3.5-4.5 mg/dL

AST (aspartate aminotransferase)

• 5-40 units/L

ALT (alanine aminotransferase)

• 8-20 units/L

ALP (alkaline phosphatase)

• 42-128 units/L

Amylase

• 56-90 IU/L

Lipase

• 0-110 units/L

Total bilirubin

• 0-1 mg/dL

Direct (conjugated) bilirubin

• 0-0.3 mg/dL

Indirect (unconjugated) bilirubin

• 0.1-1 mg/dL

Albumin

• 3.5-5 g/dL

Prealbumin

• 19-38 mg/dL

Alpha-fetoprotein

• <40 mcg/L

Ammonia

• 15-110 mg/dL

BUN

• 10-20 mg/dL

Serum creatinine

• 0.6-1.2 mg/dL

Creatinine clearance

• Females:  80-125 mL/min
• Males: 90-139 mL/min

Glomerular filtration rate (GFR)

• 120-130 mL/min

Fasting blood glucose

• <110 mg/dL

Oral glucose tolerance test

• <140 mg/dL

Glycosylated hemoglobin (HbA1c)

• 5% or less indicates absence of diabetes mellitus
• 5.7%-6.4% indicates prediabetes mellitus
• 6.5% or higher indicates diabetes mellitus

T3

• 70-205 ng/dL

T4

• 4-12 mcg/dL

TSH

• 0.4-6 microunits/mL

Urine specific gravity

• 1.010-1.030