Infections typically cause a high white blood cell count because these cells are the body’s way of eliminating infectious organisms —viruses, bacteria, fungi, and parasites.

A high white blood cell count is usually a sign of inflammation or infection, but it can be due to a blood-related cancer like leukemia or lymphoma. Researchers study the role of white blood cell ...

Exercise generally increases white blood cell count, but chronic overtraining can cause a WBC drop. Learn more here.