A low white blood cell count is a potentially dangerous condition that can only be discovered by a blood test. What is considered low depends on your age and sex.
White blood cells, also called the leukocytes, help fight off infections in your body. Normally you will have between 3,500 and 5,000 white blood cells per microliter of blood. Less than this is considered low. A low white blood cell count means your body's ability to fight off infections is compromised.
White blood cells come in five types: basophils, eosinophils, lymphocytes, monocytes and neutrophils.
A low white blood cell count is known as leukopenia. This condition can be a symptom of a number of diseases, such as lupus or liver disease, or can be among the effects of radiation therapy.
A low white blood cell count, especially in the "T cells" (lymphocytes), is a symptom of Human Immunodeficiency Virus, which can lead to AIDS.
Having a consistently low white blood cell count can make you much more susceptible to infections. You may have to take extraordinary precautions, such as wearing a face mask, to avoid any potential problems.