What are the other Names for this Test? (Equivalent Terms)

• Leukocyte Count
• WBC Count
• White Count

What is White Blood Cell Count? (Background Information)

• White blood cells (WBCs) serve as the body’s “defenders”. They play an important role in immune responses and help fight against infections. They are also involved in inflammatory responses, allergies, and protect against cancer development
• White Blood Cell Count is often ordered as a part of complete blood count (CBC) test, to evaluate the health condition of an individual
• WBC Counts may be ordered as part of investigations into infection, inflammatory disorders, and blood disorders, or to monitor individuals on therapies that are known to affect the white cell numbers
• WBC Count indicates an increase or decrease in total white cell numbers, but does not provide information regarding the individual types of WBCs (WBC types include neutrophils, eosinophils, basophils, lymphocytes and monocytes, and macrophages)

What are the Clinical Indications for performing the White Blood Cell Count?

Indications for performing a White Blood Cell Count include:

• Evaluation of general health condition of an individual
• Individuals with signs and symptoms suggestive of infection or inflammation, such as fever, headaches, body pain, and other findings specific to the underlying condition
• Individuals with signs/symptoms suggestive of blood disorders, such as recurrent infections, bleeding, pallor, etc.
• To monitor individuals with conditions known to affect WBC levels
• To monitor individuals on treatments, such as chemotherapy, radiation, or on drugs known to affect WBC Counts

How is the Specimen Collected for White Blood Cell Count?

Sample required: Blood

Process:

• Blood sample is drawn through a needle inserted into the vein (arm), or obtained through a finger prick
• In newborns: Blood sample is drawn from the heel after making a small nick using a scalpel. This is called heel stick

Preparation required: None

What is the Significance of the White Blood Cell Count Result?

The normal White Blood Cell Count, called the reference range for WBC, may vary slightly from lab to lab. Hence, most lab reports come with a reference range, which is used in that particular centre. A physician interprets the results based on the reference values provided.

A standard reference range in wide use is 4,500-11,000 WBCs/mcL (white blood cells per microliter).

Some conditions that may increase WBC Count (leukocytosis) include:

• Infections
• Inflammatory disorders, such as inflammatory bowel disease, rheumatoid arthritis, etc.
• Allergies
• Leukemia (some blood cancers cause increased production of abnormal WBCs)
• Severe stress

Some conditions that may decrease WBC Count (leukopenia) include:

• Bone marrow suppression due to drugs, chemotherapy, radiation, etc.
• Cancers that have spread to the bone and some types of blood cancers
• Vitamin B12 or folate deficiency
• Some autoimmune diseases, such as lupus
• Severe infections
• HIV

The laboratory test results are NOT to be interpreted as results of a "stand-alone" test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.

Additional and Relevant Useful Information:

Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider, the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.