What Causes Increase in WBC Count?

Increased white blood cell (WBC) count

An increased white blood cell (WBC) count, known as leukocytosis, can be caused by various factors, and the underlying cause may vary based on the specific type of white blood cells that are elevated. Here are some common reasons for an increase in WBC count:

  • Infection:
    • Bacterial, viral, fungal, or parasitic infections can stimulate the immune system, leading to an increase in white blood cells. The type of infection can influence which specific white blood cells are elevated.
  • Inflammation:
    • Any inflammatory condition, such as rheumatoid arthritis, inflammatory bowel disease, or other autoimmune disorders, can trigger an increase in WBC count.
  • Tissue Damage or Trauma:
    • Physical trauma, surgery, burns, or other forms of tissue damage can cause an inflammatory response, leading to elevated white blood cell levels.
  • Autoimmune Diseases:
    • Conditions like lupus, rheumatoid arthritis, or vasculitis can cause the immune system to attack healthy tissues, resulting in leukocytosis.
  • Allergic Reactions:
    • Severe allergic reactions or anaphylaxis can trigger an increase in white blood cells.
  • Leukemia:
    • Leukemia is a type of cancer that originates in the bone marrow, leading to uncontrolled production of abnormal white blood cells. This can result in a high WBC count.
  • Myeloproliferative Disorders:
    • Disorders like polycythemia vera, essential thrombocythemia, or myelofibrosis can cause abnormal proliferation of blood cells, including white blood cells.
  • Certain Medications:
    • Some medications, such as corticosteroids, lithium, or certain growth factors, can cause an increase in WBC count.
  • Chronic Smoking:
    • Smoking tobacco can lead to chronic inflammation, potentially causing an elevated WBC count.
  • Stress and Emotional Distress:
    • Psychological stress or emotional distress can affect the immune system and contribute to an increase in white blood cells.
  • Dehydration:
    • Dehydration can cause a relative increase in the concentration of white blood cells in the blood, leading to higher WBC counts.
  • Certain Cancers:
    • Besides leukemia, other cancers can stimulate the production of white blood cells, resulting in leukocytosis.

It’s important to note that an elevated WBC count is a non-specific marker of inflammation or immune system activation. Further diagnostic tests, such as differential blood counts and additional laboratory or imaging studies, may be needed to identify the specific cause of leukocytosis. If you have concerns about an elevated WBC count, it’s advisable to consult with a healthcare professional for a comprehensive evaluation and appropriate management based on the underlying cause.