A low white blood cell count, known as leukopenia, is defined as less than 3,500 white blood cells per microliter of blood. Discovery of a low white blood count, WBC, most often occurs when blood tests are ordered for a current condition already being experienced by the patient. Viral infections, drugs, cancer, autoimmune disease, overwhelming infections and congenital disorders can diminish the WBC or destroy the bone marrow where the leukocytes are made.
Symptoms
White blood cells, or leukocytes, fight disease in the body. A low WBC is generic to many diseases, therefore it is rare to find a low WBC without first having an existing condition. For every condition or disease, there is a completely different list of symptoms, a low WBC being amongst them. However, according to MayoClinic.com, there is a common factor that occurs with leukopenia, and that is increased vulnerability to infection. Flu-like symptoms, including chills, fever, diarrhea and stomach cramps, may occur as an already overtaxed immune system, the white blood cells, are already trying to fight off infection and disease.
Types of White Blood Cells
There are several different types of white blood cells, each with a specific disease-fighting activity. According to the University of Massachusetts Hematology Oncology Division, these can be categorized into two main types, lymphocytes and neutrophils. Lymphocytes battle against viral infections and neutrophils fight bacterial infections.
Neutropenia
The most common type of leukopenia is a lack or absence of neutrophyl granulocytes, or neutropenia. Neutrophils make up approximately 60 percent of white blood cells. The University of Massachusetts Medical School notes that the normal neutrophil count, ANC, is 4,000 to 10,000/ul.
