Leukocyte is a general term for a white blood cell. Human Leukocytes include lymphocytes, polymorphonuclear leukocytes and monocytes. . Human White blood cells are produced in the bone marrow and help to defend the body against infectious disease and foreign materials as part of the immune system. Human Leukocytosis is very common in acutely ill patients. It occurs in response to a wide variety of conditions, including viral, bacterial, fungal, or parasitic infection, cancer, and exposure to certain medications or chemicals.
White blood cells in the urine usually indicate a urinary tract infection.