Variant lymphocytes

White blood cells, also called leukocytes, are part of your immune system. They are a type of blood cell made in your bone marrow and found in your blood and lymph tissue (part of your immune system). If you are injured or get sick, the white blood cells will travel through your bloodstream and tissues to where they are needed.

A white blood count is most often used to help diagnose or monitor disorders related to having a high white blood cell count or low white blood cell count.