Neutropenia is a low number of certain white blood cells (neutrophils) in the body. These white blood cells are produced in bone marrow and help to keep the body free of infection. People with neutropenia have an increased risk of bacterial and fungal infection. When white blood cell count goes down, the risk of infection goes up. Neutropenia can be cause by a variety of illnesses and some medications.

Symptoms and Diagnosis

Neutropenia does not typically cause symptoms. Most people discover they have low white blood cell counts when they go to the doctor for an infection or illness. A complete blood count test can detect neutropenia. The severity of neutropenia ranges from mild (1000 to 1500 neutrophils per microliter of blood) to severe (less than 500 neutrophils per microliter of blood). Neutropenia can be acute or chronic, lasting longer than three months.


There are many possible causes of neutropenia. The most common cause is decreased production of neutrophils in the bone marrow, which can result from aplastic anemia, cancer, certain medications, radiation, or vitamin deficiency. Congenital neutropenia and cyclic neutropenia are genetic disorders that affect bone marrow function and cause neutropenia. Chemotherapy drugs can cause neutropenia by killing off white blood cells along with cancer cells. Autoimmune disorders can also destroy neutrophils or bone marrow cells. Certain medications, such as antibiotics and diuretics, sometimes result in low white blood cell counts. Additionally, viral infections can interrupt bone marrow function, resulting in mild neutropenia.


People with neutropenia are more vulnerable to infections, so it is important to wash hands frequently, avoid contact with sick people, and wear a facemask if necessary. It is also recommended that people with neutropenia avoid unpasteurized foods, hot tubs, ponds, and rivers, and animal waste.


There is no specific treatment for neutropenia. Treating underlying conditions often restores bone marrow function so that enough white blood cells can be produced. If a medication is the source of neutropenia, switching to another when possible is recommended.

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