Leukocytosis ? High white blood cells fight infection, but can also be a sign of other causes. Learn more about the complications & treatment. Leukocytosis is a condition with high white blood cell count, which can be caused by infections, inflammation, bone marrow disorders, and other factors. Learn how to diagnose and treat leukocytosis , and what are the possible complications and ICD-10 codes. Leukocytosis is a high white blood cell count, and it can cause symptoms due to the actions of thw white blood cells in the body. Learn about the causes, symptoms, diagnosis and treatment of leukocytosis , a condition where the white blood cell count is above normal. Find out how infections, medications, cancers and other factors can affect the white blood cell count.