Fever is normally the body’s response to infection. Experiencing a fever during chemotherapy requires immediate treatment. Chemotherapy causes a low white blood cell count in the blood. Without a normal level of white blood cells, the body cannot fight the infection. This could quickly lead to serious illness. 

This article will define chemo fever and describe the steps to take when it occurs. 

Definition

Chemo fever is a fever that occurs during or after receiving chemotherapy treatment. When you experience a fever during a round of chemotherapy, it is important to call your doctor right away. 

Chemotherapy lowers your body’s ability to fight infection by decreasing your white blood cell count. This is known as neutropenia. It’s estimated that about 5%–25% of individuals receiving chemotherapy will experience a neutropenic fever at some point during treatment. 

Diagnosis

If you are experiencing a fever during a round of chemotherapy, it’s important to let your medical team know right away so they can determine the cause of your fever. The doctor or nurse will start by asking questions about your symptoms and treatment plan. They will likely ask about your chemotherapy schedule and when your last dose was administered. 

They will also ask if you are experiencing any other symptoms in addition to the fever. Symptoms to alert your medical team about include:

Skin soresRedness, swelling, or pus around an IV (intravenous) siteNew-onset painCoughMouth sores 

Your doctor may also recommend the following blood tests to evaluate your fever:

Complete blood count (CBC): A complete blood count will show your level of white blood cells and help the medical team determine your risk of infection. Blood culture: A blood culture may be drawn to determine which type of virus or bacteria is causing infection.  

Treatment

A fever during chemotherapy treatment may be a medical emergency because an infection can quickly spread throughout the body and lead to sepsis, an extreme, life-threatening response to infection. As soon as you realize you have a fever, call your doctor right away. Your medical team will work with you to determine the cause of your fever.

Over-the-Counter (OTC) and Home Remedies

Once your medical team has determined that your fever is being caused by chemotherapy and not an underlying infection, they may recommend over-the-counter medication, such as Tylenol (acetaminophen), to treat the fever and relieve any other symptoms. It’s important to talk with your doctor before taking medication to treat a fever. 

Chemotherapy often causes a low platelet count. Platelets are cells in the blood that clot the blood and prevent bleeding. If you have a low platelet count, your doctor will advise you to avoid any nonsteroidal anti-inflammatory drugs (NSAIDs), like Advil or Motrin (ibuprofen) or aspirin, as these drugs can cause bleeding.

Home remedies to help relieve fever symptoms include drinking fluids, resting, and using a cold compress on your forehead.

Medications

If your doctor discovers or suspects that your fever is due to an infection, they will start treatment right away. Treatment options include:

Antibiotics: You will most likely receive a broad-spectrum antibiotic that is able to treat several types of infection. Once the medical team determines which virus or bacterium is causing the infection, you may receive a more specific antibiotic.   Colony-stimulating factors: Colony-stimulating factors, such as Neupogen (filgrastim), are drugs that work to boost the white blood cell count in the blood. These drugs can be given by IV or subcutaneously (SQ) injection and help the body to better fight the infection.   OTC medications: Your medical team may recommend taking Tylenol (acetaminophen) to relieve your symptoms.

Prevention

There is no way to always prevent chemo fever. The best option is to be prepared with a plan for when a fever occurs.

Talk with your doctor about possible chemotherapy side effects and how to address them. Make sure that you have a working thermometer at home in a convenient spot. Know your doctor’s phone number or have it posted somewhere visible. Finally, if you have to go to the emergency room because of a fever, tell the health providers right away that you are receiving chemotherapy treatment. 

When to Call the Doctor 

During chemotherapy treatment, call your doctor anytime you develop new symptoms, especially a fever. Anytime you feel warm, chilled, flushed, or just “off,” take your temperature. Any temperature above 100.4 degrees Fahrenheit or 38 degrees Celsius is considered a fever. 

Other symptoms often associated with fever include:

HeadacheShaking chillsBody achesSkin rash Abdominal painSore throat Feeling confused or forgetful 

Summary

Chemo fever is a possible side effect of chemotherapy. It’s also possible to experience an infection that leads to fever. Chemotherapy affects the body’s ability to fight infection, so it is very important to call your doctor as soon as you develop a fever. Your doctor will likely perform lab tests to determine the cause of your fever and may admit you to the hospital for antibiotic treatment. 

A Word From Verywell 

Cancer treatment can often feel grueling, and several side effects are possible. If you experience a fever during your treatment, it may be due to chemotherapy, or it could be caused by an infection. Always take your temperature as soon as you feel ill and call your doctor right away.