A low white blood cell count is an indicator of serious infections, bone marrow deficiency, autoimmune disorders and certain types of cancer, according to MedlinePlus. Several types of medications, such as anti-seizure drugs and chemotherapy drugs, also cause decreased WBC counts.Continue Reading
White blood cells help the immune system fight infections, explains MedlinePlus. A normal WBC count ranges from 4,500 to 10,000 cells per microliter. Mononucleosis, spleen disorders, liver diseases and lupus are some of the causes of a reduced WBC count. Antibiotics, diuretics and anti-thyroid drugs can also reduce the number of WBCs in the blood.
There are five major types of white blood cells, notes the University of Rochester Medical Center. Basophils let other white blood cells know when a foreign substance has entered the bloodstream and participate in the body's immune response by releasing histamine and other chemicals. Eosinophils participate in the allergic response, destroy parasites and kill cancer cells. Monocytes break down bacteria, preventing infections from getting out of control. Lymphocytes defend the body against infections by producing antibodies to certain organisms. Neutrophils are the first WBCs to respond when a foreign substance infects the body. They help the body fight infection by digesting fungi and bacteria.Learn more about Medical Ranges & Levels