Neutropenia (noo-troe-PEE-nee-uh) is an abnormally low count of neutrophils, a type of white blood cell that helps fight off infections, particularly those caused by bacteria and fungi.

What Is Neutropenia?

Neutropenia is an abnormally low count of a specific type of white blood cell called a neutrophil. Neutrophils are stored in the bone marrow * and are the most common type of white blood cell, comprising between 45 and 75 percent of all the white blood cells. They are responsible for protecting the body against infection. When the neutrophil count is low (neutropenia), the body is at high risk for infection. Neutropenia can be classified as mild, moderate, or severe. The risk for infection increases as the neutropenia becomes more severe and also increases the longer the individual is neutropenic.

What Are the Causes of Neutropenia?

The most common cause of neutropenia is treatment with chemotherapy * or radiation therapy * for cancer. Chemotherapy drugs and radiation therapy kill body cells that are rapidly dividing, but they cannot tell the difference between normal cells and cancer cells, so while attacking cancer cells, they also damage or kill normal cells.

Additional causes of neutropenia include the following:

In infants, the most common cause of neutropenia is infection * . A severe infection may prevent the bone marrow from producing enough neutrophils. Neutropenia may also occur in infants when the mother had preeclampsia * during pregnancy. Neutropenia in infants is a lifethreatening condition.

Who Is at Risk for Neutropenia?

People who are receiving chemotherapy for cancer are at highest risk for the development of neutropenia. Neutropenia occurs most commonly about 7 to 12 days after receiving a chemotherapy treatment.

Level of risk can vary with the different possible causes of neutropenia as described previously.

What Are the Signs of Neutropenia?

Although there are no obvious signs of neutropenia, frequent or unusual infections or infections that do not heal quickly may be indicators of neutropenia. Signs of infection include the following:

Neutrophils are a type of white blood cells that protect the body from infection. They constitute about 45 to 75 percent of all white blood cells in the bloodstream.

Neutrophils are a type of white blood cells that protect the body from infection. They constitute about 45 to 75 percent of all white blood cells in the bloodstream.
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When signs of infection occur and do not resolve or get worse, the person should see a doctor for evaluation and treatment.

What Is the Treatment for Neutropenia?


The doctor orders a blood test that provides a count of white blood cells with a breakdown of the types of white blood cells, including neutrophils. This test tells whether or not the neutrophil count is normal or too low. A bone marrow biopsy * may be required to determine the cause of the low neutrophil count.

The doctor may order laboratory tests (called cultures * ) of the blood and urine to determine if there is infection present and which antibiotics * will be most effective for treatment.


Treatment is often targeted toward clearing up any existing infection. When a person has neutropenia, an infection is a serious event that can lead to serious complications or death.

When the cause of the neutropenia is found, treatment will be targeted toward the cause. For example, if the cause of the neutropenia is an enlarged spleen, surgery to remove the spleen may resolve the problem.

Special medications that are designed to stimulate the production of white blood cells, including neutrophils, may be prescribed by the doctor. In patients receiving chemotherapy known to cause severe neutropenia, these medications may be ordered prior to the start of treatment with chemotherapy.

Results of cultures of the blood, urine, sputum, and/or wounds are used to determine therapy using specific antibiotics. If fever does not respond to antibiotic therapy within four to five days of initiation of treatment, antifungal medications may be ordered as the patient may have a fungal infection. Most severely neutropenic patients will be treated with intravenous antibiotics in an hospital setting where the effects of the antibiotics can be closely monitored.

Can Neutropenia Be Prevented?

A person may not be able to prevent neutropenia, but he or she can take precautions to avoid getting an infection.

Strategies to decrease the risk of getting an infection include: