Information for Patients and Caregivers

Photo of a man receiving chemotherapy

People with cancer who are treated with chemotherapy are more likely to get infections because of their weakened immune system.

People with cancer who are treated with chemotherapy are more likely to get infections because of their weakened immune system. Cancer and chemotherapy can damage your immune system, reducing your numbers of infection-fighting white blood cells and making it harder for your body to fight infections. An infection can also lead to sepsis, the body’s overwhelming and life-threatening response to an infection.

What Is an Infection?

You get an infection when germs enter your body and multiply, causing illness, organ and tissue damage, or disease. Bacteria and viruses cause infections.

  • You can get bacteria from the air, water, soil, or food during the course of your medical treatment. Most bacteria come from your own body. Common bacterial infections include pneumonia, bronchitis, and ear infections.
  • Viruses are passed from one person to another. Common viral infections include the common cold, herpes, and the flu.

How Does Chemotherapy Increase My Risk for Getting an Infection?

Diagram showing how chemotherapy increases risk for infections. Chemotherapy drugs are used to treat cancer by killing the fastest-growing cells in the body; both good cells and cancer cells. Neutropenia is a side effect of chemotherapy that means your body has fewer than normal infection-fighting white blood cells. Infection is when germs enter your body and cause illness. Neutropenia can lead to infection.

What Should I Do If I Think I Have an Infection?

Call your doctor right away, even if this happens in the middle of the night. This is considered an emergency. Don’t wait until morning. Keep your doctor’s phone numbers with you at all times. Make sure you know what number to call during your doctor’s office hours, as well as after hours.

Photo of a man with a thermometer and an ice pack.
If you get a fever during your chemotherapy treatment, it’s a medical emergency. Fever may be the only sign that you have an infection, and an infection during chemotherapy can be life-threatening.
Photo of a person washing hands.
Many diseases are spread by not cleaning your hands, which is especially dangerous when you’re getting chemotherapy treatment because your body may not be able to fight off infections like it used to.
Photo of a man having a fever.
Infection during chemotherapy can lead to hospitalization or death. Call your doctor right away if you notice any of the signs and symptoms of an infection.
Caregiver putting her hand on the head of a cancer patient who has fever.
Neutropenia is a decrease in the number of white blood cells. These cells are the body’s main defense against infection. Neutropenia is common after receiving chemotherapy and increases your risk for infections.
Page last reviewed: November 5, 2018