Last Updated on January 29, 2025 by Analgesia team
White Blood Cell Function (WBC)
White blood cells, also known as leukocytes, are cells in your blood that help your body fight infection and disease. They are part of your immune system and are produced in your bone marrow.
White blood cells (WBCs) are measured using a blood test that counts the number of white blood cells in a sample of blood. This test is often part of a complete blood count (CBC).
How white blood cell functions
- White blood cells travel through your bloodstream and lymph tissues.
- When your body detects an infection, white blood cells rush to the site to destroy the harmful substance.
- Some white blood cells directly attack the infection by surrounding and engulfing the invading pathogen.
- Other white blood cells, like lymphocytes, produce antibodies to fight the infection.
Types of white blood cells
- Neutrophils: Fight bacteria and fungal infections
- Eosinophils: A type of granulocyte
- Basophils: A type of granulocyte that secretes histamine and heparin
- Monocytes: A type of white blood cell
- Lymphocytes: A type of white blood cell that includes T cells and B cells
White blood cell count
- A white blood count (WBC) measures the number of white blood cells in your blood.
- When you are sick, your body produces more white blood cells, which increases your WBC.
- Some diseases and certain medicines can lower your WBC.
- A normal WBC count is between 4,500 and 11,000 WBCs per microliter.
Low white blood cell count
- A low white blood cell count can cause you to get frequent infections.
- Signs of an infection include fever, chills, sore throat, mouth sores, toothache, skin rashes, tiredness, and flu-like symptoms.
- Also known as leukopenia, this can be caused by bone marrow damage, cancer, autoimmune disorders, or HIV.
High white blood cell count
Also known as leukocytosis, this can be a normal immune response to infection or inflammation. It can also be caused by stress, anxiety, pregnancy, or a reaction to medication.