Neutropenia: Causes, Symptoms, Treatment

Medically Reviewed by Zilpah Sheikh, MD on December 07, 2023
6 min read

Neutropenia is a condition in which you have an unusually low number of cells called neutrophils in your blood. Neutrophils are a type of white blood cell in your immune system that attack bacteria and other organisms when they invade your body.

Your bone marrow, which is tissue found in bones that makes cells, creates neutrophils. They then travel in your bloodstream and move to areas of infection where they are taken in and then cancel out bacteria. Having a lower than normal number of neutrophils in your blood can make it harder to fight germs and prevent infections.

Neutropenia can be temporary (acute) or last 3 months or more (chronic) and can affect both children and adults. There are four main types of neutropenia:

Congenital neutropenia. This is a severe form of neutropenia that is seen most often in babies or very young children. When a condition is congenital, it means it is present at birth. The most serious form of chronic congenital neutropenia is called Kostmann's syndrome. In people with this condition, neutrophils in the bone marrow may not develop fully enough to fight infections.

Idiopathic neutropenia. The term idiopathic means "of unknown cause." Idiopathic neutropenia affects children and adults.

Cyclic neutropenia. This type of neutropenia usually occurs every 3 weeks and may last 3-6 days or longer. It affects both children and adults, sometimes within the same family. Cyclic neutropenia happens when the rate of cell production in a person's bone marrow rises and falls.

Autoimmune neutropenia. This is the most common cause of neutropenia in infants and young children. Occasionally, it is seen in adults aged 20-40 years (mostly women). The condition causes the body's immune system to fight and destroy its own neutrophils.

Febrile neutropenia. While not one of the four main types of neutropenia, febrile neutropenia is a serious side effect for people with cancer who are treated with chemotherapy. When your immune system is suppressed, an oral temperature of greater than 101 F or a fever of at least 100.4 F that lasts an hour or more can be a sign of a dangerous infection.


Neutropenia itself often doesn't cause symptoms. In some cases, people only learn they have neutropenia when they have a blood test for an unrelated reason. It is most commonly seen—and even expected—as a result of chemotherapy used to treat cancer. But some people may have other symptoms from an infection or underlying problem causing the neutropenia.

Infections can occur as a complication of neutropenia. They occur most often in the mucous membranes, such as the inside of the mouth and the skin.

These infections can appear as:

  • Sore throat
  • Swollen lymph nodes
  • Ulcers around the mouth or your anus
  • Burning sensation with pee or urgent and/or frequent need to pee
  • Diarrhea
  • Swollen areas filled with pus (abscesses)
  • Pain, swelling, and/or rash where the infection is
  • Long-lasting wounds
  • Fatigue

Fever is also a common symptom of infection. In a neutropenic fever, it's common not to know the exact cause, which is often normal gut bacteria that has made its way into the blood from weakened borders. Neutropenic fevers are usually treated with antibiotics, even if an infectious source can't be confirmed. This is important because the weakened immune system means people can get very sick very quickly.

The risk of a serious infection generally raises as:

  • Neutrophil count goes down
  • Duration of severe neutropenia gets longer

Causes of neutropenia include:

  • Problem in the production of neutrophils in the bone marrow
  • Destruction of neutrophils outside the bone marrow
  • Infection
  • Nutritional deficiency

Causes of lowered production of neutrophils include:

  • Being born with a problem with bone marrow production (congenital)
  • Leukemia and other conditions that affect the bone marrow or lead to bone marrow failure
  • Radiation
  • Chemotherapy

Infections that can cause neutropenia include:

  • Tuberculosis
  • Dengue fever
  • Viral infections such as Epstein-Barr virus, cytomegalovirus, HIV, viral hepatitis

Raised destruction of neutrophils can be due to viral infections or medications used to treat autoimmune disorders targeting neutrophils for destruction. This may be related to conditions such as:

  • Crohn's disease
  • Rheumatoid arthritis
  • Lupus

In some people, neutropenia can be caused by certain medications, such as:

  • Certain antibiotics, like vancomycin, penicillin G, and oxacillin
  • Drugs used to treat irregular heart rhythms, including quinidine and procainamide
  • Antiviral drugs, like ganciclovir and valganciclovir 
  • Drugs used to treat overactive thyroid, such as methimazole and propylthiouracil
  • Blood pressure medications
  • Some psychiatric drugs, such as clozapine and chlorpromazine
  • Epilepsy drugs (rare)
  • Some anti-inflammatory medications for conditions like ulcerative colitis or rheumatoid arthritis, including sulfasalazine

Neutropenia can be diagnosed with a simple blood test called a complete blood count with differential. If you are treated with chemotherapy, your doctor will likely monitor your neutrophil levels with regular blood work.

If the cause of your neutropenia is unknown, your doctor may want to order additional tests, such as a bone marrow biopsy, to find out if your body is making neutrophils normally.

When deciding on treatment, doctors consider the cause and severity of neutropenia. Mild cases may not need any treatment.

Approaches for treating neutropenia can include:

  • Antibiotics for fever. In neutropenic fever, the assumption is made that there is an infection causing the fever even when the source can't be found.
  • Granulocyte colony-stimulating factor. This treatment stimulates the bone marrow to produce more white blood cells. It is used for several types of neutropenia, including low white cell count from chemotherapy. This treatment can be lifesaving in these cases.
  • Changing medications. Updating the medications you're taking may be recommended in cases of neutropenia caused by taking certain drugs.
  • Granulocyte (white blood cell) transfusion. This treatment is often used in people who've had chemotherapy or bone marrow transplants.
  • Corticosteroids. These medications may be recommended if you have an autoimmune condition to help reduce your body's immune response and stop it from attacking the neutrophils.
  • Stem cell transplants. These may be useful in treating some types of severe neutropenia, including those caused by bone marrow problems.

People with neutropenia often need to take special steps to prevent infections. Some precautions to prevent neutropenia-related infections include:

  • Good hygiene, including frequent handwashing and good dental care, such as regular tooth brushing and flossing
  • Staying up to date on vaccinations
  • Avoiding contact with sick people
  • Always wearing shoes
  • Cleaning cuts and scrapes and then covering them with a bandage
  • Avoiding or properly caring for tattoos and piercings
  • Using an electric shaver rather than a razor
  • Avoiding animal waste and, when possible, not changing infants' diapers
  • Avoiding unpasteurized dairy foods, undercooked meat, and raw fruits, vegetables, grains, nuts, and honey
  • Staying out of hot tubs, ponds, and rivers
  • Avoiding sharing razors, toothbrushes, and towels with others
  • Avoiding eating or drinking from other people's utensils or cups

Neutropenia affects your body's ability to fight infections. If you're diagnosed with neutropenia, it's important to see your doctor to discuss a treatment plan. This may include regularly monitoring your neutrophil levels or taking medications to prevent infections.

What is the primary cause of neutropenia?

Neutropenia is common in people who are receiving cancer treatments like chemotherapy but can also be caused by infections, autoimmune conditions, lack of certain nutrients in your diet, or medications you're taking. It can also be inherited.

What does it mean if you have neutropenia?

If you have neutropenia, you have a low number of neutrophils, which is a type of white blood cell.

How do you fix neutropenia?

Some forms of neutropenia may not require treatment, like forms that people can be born with or that don't raise infection risks. Other treatment plans depend on the cause of neutropenia and may include corticosteroids, antibiotics, and other medications.