This section has been reviewed and approved by the PLWC Editorial Board, 02/05

Neutropenia is an abnormally low level of neutrophils, a type of white blood cell. All white blood cells help the body fight infection. Neutrophils fight infection by destroying bacteria. Patients who have neutropenia are at increased risk for developing serious bacterial infections because there are not enough neutrophils to destroy harmful bacteria. Neutropenia occurs in about 50% of patients receiving chemotherapy and is common in patients with leukemia.


Neutrophils and other types of white blood cells are made in the bone marrow (a spongy, fatty tissue found inside larger bones). Cancer and cancer treatment can cause neutropenia in several ways:

  • Some chemotherapy drugs can cause the bone marrow to malfunction, lowering the production of neutrophils.
  • Cancers that affect the bone marrow directly (including leukemia or lymphoma) can crowd normal bone marrow cells.
  • Radiation therapy can also affect the bone marrow, especially if given to extensive areas of the body or to bones in the pelvis, legs, chest, or abdomen.

Patients with cancer who are 70 or older or who have a weakened immune system (due to factors such as HIV infection or a kidney transplantation) are at higher risk for neutropenia. In addition, people with severe or long-lasting neutropenia are more likely to develop an infection.

Signs and symptoms

Neutropenia itself does not cause any symptoms. Patients usually find out they have neutropenia from a blood test or when an infection develops. Because neutropenia is a common side effect of certain types of chemotherapy, the doctor will do regular blood tests, usually a complete blood count (CBC), to look for neutropenia and other blood-related complications of chemotherapy.

For patients with neutropenia, even a minor infection can quickly become serious. Talk to your doctor right away if you experience any of the following signs of infection:

  • A fever (temperature of 100.5F or higher)
  • Chills or sweating
  • A sore throat or sores in the mouth
  • Abdominal pain
  • Diarrhea or sores around the anus
  • Pain or burning when urinating or frequent urination
  • A cough or breathlessness
  • Any redness, swelling, or pain, particularly around a cut or wound
  • Unusual vaginal discharge or itching

Management and treatment

Depending on the type or dose of chemotherapy, neutrophil counts generally start to drop about a week after each round of chemotherapy and usually reach a low point (called the nadir) about seven to 14 days after treatment. Patients are most vulnerable to infection at this point. The number of neutrophils then starts to rise again and may take three to four weeks to reach a normal level. When the neutrophil level returns to normal, another round of chemotherapy can begin. If the patient develops neutropenia or the neutrophil level does not return to normal quickly enough, the doctor may delay the next round of chemotherapy or recommend a lower dose.

If the chemotherapy commonly causes neutropenia or if neutropenia is interfering with the patient's ability to tolerate chemotherapy, the doctor may decide to use medications called blood growth factors. These include filgrastim (Neupogen), pegfilgrastim (Neulasta), or sargramostim (Leukine or Prokine) and they encourage the body to make more neutrophils or other types of WBCs.

More Information

Managing Side Effects: Infection

PLWC: Managing Side Effects Neutropenia

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