A diagram of the effects of leukemia, a disease that can cause a low white blood cell count.
White blood cells are essential for the healthy function of the immune system, as they help fight infections and other abnormalities in the blood, bone marrow, and lymphatic system. There are several different types of white blood cells, each of which is essential for defending the body against a certain disease, such as a bacteria, virus, fungus, parasite, or allergic reaction. If a person has a low white blood cell count, his body becomes susceptible to serious illness and infection. A low white blood cell count may indicate the presence of one or more serious health problems, such as leukemia, hyperthyroidism, aplastic anemia, or an infectious disease. Not enough cells can also be a potentially dangerous side effect of taking certain medications or receiving chemotherapy and radiation treatments.
A white blood cell.
It is common for a person with cancer to have low white blood cell counts. A specific type of cancer known as leukemia is particularly devastating to blood cells and the immune system in general. Leukemia directly affects the tissue that makes up the bone marrow, which in turn leads to fewer healthy white blood cells and a large number of mutated and harmful cells. Doctors can test for leukemia and other types of cancer by ordering blood tests and bone marrow extraction to determine the number and condition of white blood cells. Leukemia is usually treated with chemotherapy, radiation therapy, or bone marrow transplants.
A diagram showing different types of white blood cells.
Unfortunately, the most popular treatments for leukemia and other cancers can also result in low white blood cell counts. Chemotherapy and radiation therapy aim to seek out and destroy abnormal cells, but innocent, healthy white blood cells can also be damaged during treatment. Many other medications, including some antipsychotics and antidepressants, can deplete white blood cells with long-term use. Doctors often prescribe immune-enhancing drugs to patients to counteract the negative effects of cancer treatments and other medications.
Blood tests are used to measure the levels of white blood cells.
A low white blood cell count can also indicate the presence of a serious bacterial, viral, or fungal infection that attacks the immune system, such as the human immunodeficiency virus (HIV). Some congenital diseases, such as lupus and myelofibrosis, cause the body to attack its own defense system, depleting the bone marrow and white blood cells. People can suffer from aplastic anemia, a condition in which the body cannot make new blood cells. Vitamin or mineral deficiencies, the flu, typhoid fever, and malaria can also cause a low white blood cell count.
