June 30, 2020

Why You Should Take Fevers Seriously If You Have Cancer

When undergoing cancer treatment, fever is a critical symptom to address

man in bed with fever and cough

A fever may not send most people to the doctor’s office. But if you have cancer, the combination of fever, weakness and pain could mean an infection — and require a visit to the emergency room.


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When a person’s immune system is compromised by cancer and its treatments, it’s harder to recover from even common illnesses. And some of these illnesses can even become life-threatening.

That’s why you need to take special care if you are undergoing cancer treatment and happen to develop signs of infection, including fever, chills, abdominal pain and a productive cough.

If this happens, make sure you:

  1. Call your oncologist immediately — especially if you have a temperature of 100.5 degrees Fahrenheit (38 C) or higher.
  2. Go to an emergency room, if instructed by your oncologist.
  3. Clearly indicate that you are undergoing cancer treatment.

Conditions that may prompt an ER visit

In terms of urgency, some symptoms are more pressing than others. If you’re experiencing pain, weakness, shortness of breath, vomiting and diarrhea, go to the hospital.

“If a patient feels like they need to be seen, then they should come in,” says Emergency Medicine Director Tom Waters, MD. “You can’t quantify how bad someone should feel before seeking help.”


But there’s one symptom that indisputably requires a trip to the hospital: fever. Everyone who has cancer and is undergoing chemotherapy needs immediate attention if they have a temperature of 100.5 degrees Fahrenheit (38 C) or higher.

Fever, the critical symptom

Chemotherapy can often lead to a reduced white blood cell count, or neutropenia. This condition causes the body to be less effective at fighting off infection. Neutropenic fever is common in those who are getting chemotherapy and it can often signify infection. If you have a weakened immune system, infections need to be treated immediately before they cause greater complications.

“About 5 to 25% of patients receiving chemotherapy will get neutropenic fever,” says hematologist and oncologist Omer Koc, MD. “The more aggressive the chemotherapy, the higher the risk. Age and other underlying illnesses also play a role.”

Treating neutropenic fever

According to Dr. Waters, anyone who has cancer with a fever or other condition that’s an emergency should call their oncologist immediately. The oncologist will determine if they should go directly to an emergency room or to the doctor’s office.

If you go to an emergency room, you should clearly tell them up front that you are undergoing cancer treatment. It will make a difference in how you are triaged.


“A healthy patient with a fever and cough might get a flu swab or throat swab or chest X-ray,” explains Dr. Waters. “We may give them acetaminophen and send them home to rest. But someone who has cancer with the same symptoms will need a more intense evaluation to find the source of their infection.”

Dr. Waters says they’ll keep anyone who has cancer in isolation to prevent exposure to any new infections while they do a culture of their blood and urine to check for bacteria.

“We’ll start them on antibiotics right away until we identify the cause of their fever. We can always stop the antibiotics later if we find they don’t have an infection,” Dr. Waters explains.

The important thing if you have cancer and develop a fever is to get medical attention right away.

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