Normal Lab Values For Nursing

Normal Lab Values For Nursing

As a nursing student, you’ll spend a lot of time looking at lab values. You’ll probably have to interpret them on your own and explain them to patients or their families. In this guide, we break down each of these common lab values into an easy-to-understand format so that you can quickly understand what they mean and how they should be used in practice.


Hemoglobin is a protein in red blood cells that carries oxygen from the lungs to the rest of the body. It is measured in grams per deciliter (g/dL).


The hematocrit is the percentage of red blood cells to total circulating volume. Normal range for males is 43-52%; normal range for females is 37-47%. You can calculate hematocrit by dividing the red cells by your volume of whole blood and multiplying this number by 100.


Platelets are a type of blood cell that help the body form clots. They have a lifespan of about 10 days and can be decreased by chemotherapy, infection or autoimmune disorders.

White Blood Cells

White blood cells (WBCs) are a type of blood cell that helps fight infection. They are also called leukocytes, which means “white” in Greek. The amount of WBCs in your body is measured by a lab test called a complete blood count (CBC).

Normal WBC counts range from 3,500 to 11,000 white blood cells per microliter (µL) of whole blood. Abnormal WBC counts may indicate an infection or disease process.


Potassium is an electrolyte, which means it conducts electrical current. It also helps regulate blood pressure and is important for muscle contractions, nerve impulses, and the transmission of fluids and nutrients through cell membranes.

Potassium levels are measured in milliequivalents per liter (mEq/L). Normal potassium values range from 3.5 mEq/L to 5 mEq/L (3.5 to 5).

Potassium can be lost through urine or sweat; therefore it is important to replace potassium when you lose it in either way.


The normal range of sodium is 135-145 mmol/L. This value is indicative of a well-hydrated individual who has consumed a healthy diet. Values less than 135 mmol/L indicate dehydration and values greater than 145 mmol/L may be indicative of excessive fluid intake or kidney disease.


Chloride, or Cl−, is an electrolyte that helps maintain the body’s acid-base balance.

Normal Range: 97-107 mmol/L (mEq/L) or 47-52 mEq/L

Anion gap: 10-14 mEq/L

Chloride low (hypochloremia): 108 mmol/(l)(mEq)/l; causes metabolic alkalosis


Bicarbonate is a buffer in the body and it’s also a component of blood. It is an ion that helps to maintain pH levels. The normal range for bicarbonate is 22-28 mEq/L.

There are many things that can affect the bicarbonate level in your blood, such as:

  • The amount of fluid you drink
  • How much sodium you eat
  • Exercise or other physical activity


Magnesium is the fourth most abundant mineral in the body, and it’s also an essential element for many biochemical reactions. Magnesium is important to many critical body functions, including cardiovascular health and bone maintenance.

Magnesium deficiency can cause symptoms such as muscle weakness and cramps, decreased energy levels, irregular heartbeat (arrhythmias), depression and fatigue. Extreme magnesium deficiency may lead to cardiac arrest or sudden death due to arrhythmias related to impaired calcium metabolism.

Creatinine Clearance (CrCl)

Creatinine clearance is a measure of the rate of filtration of creatinine in the kidneys. Creatinine is a waste product created in muscle tissue, which is then converted to urea by the liver and excreted by your kidneys. The amount of creatinine that remains in your blood reflects how effectively your body eliminates wastes.

  • Creatinine – A waste product made by muscle tissue that’s filtered out through urination.* Urea – A chemical compound produced when amino acids are broken down for energy.* Kidneys – Two fist-sized organs located on either side of your back (one on each side) that help regulate fluid balance, blood pressure and remove excess water from urine.* Filtrate – The fluid filtered into Bowman’s capsule each time blood passes through kidney tubules; it contains nutrients needed to meet daily needs while also disposing of excess water out through urine as well as other substances such as drugs or toxins that have been filtered into Bowman’s capsule but not reabsorbed into circulation yet…

Glucose, Serum

Glucose, Serum

Normal range: 70–110 mg/dL

#Hypoglycemia occurs when blood sugar is less than 70 mg/dL.

#Hyperglycemia occurs when blood sugar is greater than 110 mg/dL.

Blood Urea Nitrogen (BUN)

Blood Urea Nitrogen (BUN) is a by-product of protein metabolism. The kidneys are responsible for regulating the BUN level in your blood, and this number can be used to determine kidney function. If you have chronic kidney disease (CKD), your doctor may order a urea nitrogen test periodically to see if your treatment is working or if he/she needs to make any changes.

The liver is also responsible for regulating blood urea nitrogen levels by filtering it out of circulation into bile and then sending it back into circulation through urine when the liver cannot use or store amino acids anymore. If someone has liver problems that affect their ability to excrete urea, their BUN levels will be elevated above normal. Additionally, an abnormally high level could indicate dehydration or malnutrition since both conditions lead to lower levels of water-soluble vitamins like thiamine which are required for proper metabolism of proteins into amino acids for production of enzymes needed for carbohydrate metabolism and synthesis as well as building blocks required for growth processes such as DNA synthesis during cell division.”

Serum Osmolality

Osmolality is the number of dissolved particles in a solution. This measurement can be used to determine the concentration of an electrolyte, such as sodium (Na+) or potassium (K+), or a sugar (e.g., glucose).

To calculate osmolality, you would multiply your serum’s concentration by its total volume in milliliters (mL). A normal value for serum osmolality is between 270–300 mOsm/kg H20 or 285-295 mOsm/L.[1] Note that this lab value can vary slightly based on your lab’s reference range since different labs may have slightly different ranges for their tests.[2]

Normal ranges for other types of fluids include: urine—100–800 mOsm/kg H2O; cerebrospinal fluid—280-300 mOsm/kg H2O[3]; and saliva—80-120 mOsm/L[4]. If any of these values are above or below their respective normal range, it could indicate a problem with either the kidneys, liver function or blood glucose levels.[5]

Knowing how to interpret lab values confidently is a skill all nurses must master.

Knowing how to interpret lab values confidently is a skill all nurses must master. The importance of knowing how to interpret lab values cannot be overstated. Not only does it help you understand the patient’s condition, but it also helps you provide excellent nursing care by assisting in making treatment decisions and educating patients about their health status.

Nurses need a clear understanding of normal values for each test because they’re involved with ordering so many tests in the course of their workday. They might not always have time or access to research when they’re working on the floor, which can make interpreting normal ranges challenging when they are presented with them unexpectedly or in large amounts during shift changeover meetings or educational sessions. By learning these basics now, you’ll be able to confidently interpret results as well as determine whether any of your patients require follow-up testing without needing much help from coworkers

The most important thing about interpreting lab values is to always be on the look out for what is normal and abnormal. An abnormal result could indicate the presence of an illness or disease, but it could also be due to many other things. The key is to understand what is going on before jumping to conclusions and overreacting in a way that wastes time or causes harm.

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