Though cancer and the flu are different conditions, they share many common symptoms. Things like fatigue, fever, body aches or loss of appetite can overlap, making it hard to know if what you’re experiencing is something minor or something more serious. That’s why it’s important to pay attention to symptoms that don’t go away and talk with your doctor about next steps.
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If you’ve been diagnosed with cancer and are interested in getting a second opinion of your diagnosis or treatment options, call us or chat online with a member of our team.
Does cancer cause flu-like symptoms?
“Whether it’s fatigue, chills, fever, headache or body aches, persistent cough, nausea and vomiting, some types of cancer can cause symptoms that resemble flu-like symptoms,” says Aileen Go, MD, a hematologist-oncologist at City of Hope® Cancer Center Phoenix. “This can make them easy to overlook at first, and it’s especially true for hematologic malignancies or blood cancers.”
For example, leukemia and other blood cancers may cause weakness, body aches and frequent infections. Lymphoma may lead to fatigue, fever and night sweats. Lung cancer may cause coughing, shortness of breath and chest discomfort.
Are chills a sign of cancer?
Chills are sometimes a sign of certain cancers, especially when they happen often or without a clear cause like an infection. Blood cancers such as leukemia and lymphoma are most commonly linked to chills, since they may affect how your body makes and fights off infection. Kidney cancer and other advanced cancers may also cause unexplained chills or fevers.
While chills don’t usually mean cancer, it’s important to talk to your doctor if they are recurrent, severe or accompany other unusual symptoms.
Does cancer cause fever?
While fever is often your body’s way of fighting infection, in some cases it may also be linked to cancer. Blood cancers like leukemia, lymphoma and multiple myeloma are the most common types associated with unexplained fevers. They affect the immune system, making the body more prone to fever even without infection. Kidney cancer and liver cancer may also cause fever, especially in more advanced stages.
A fever may have many causes, but most are not related to cancer. If you have a fever that keeps coming back or doesn’t have a clear cause, it’s important to contact your doctor.
Other links between cancer and the flu
Some cancer treatments cause flu-like symptoms or side effects such as fever, chills, muscle aches or fatigue.
For instance, chemotherapy may trigger these symptoms within hours of treatment, and they usually last for two or three days. Certain immunotherapy treatments may also cause flu-like symptoms because they boost your immune system. These side effects often feel strongest shortly after treatment but typically improve over time.
Some advanced immunotherapies, like chimeric antigen receptor (CAR) T-cell therapy and certain monoclonal antibodies, may cause a stronger reaction called cytokine release syndrome (CRS). CRS may lead to more serious flu-like symptoms along with issues such as rash, fast heartbeat, low blood pressure or trouble breathing.
Patients receiving cancer treatment may be immunosuppressed, meaning they have weaker immune systems. This may make them more likely to catch the flu.
When to see a doctor
If flu-like symptoms last longer than two weeks, it’s important to check in with your doctor. While these symptoms are often temporary, lasting or worsening ones could be a sign that something else is going on and should be evaluated. If you have cancer, call your oncologist promptly if you notice any new or unusual symptoms so they can gauge what’s happening.
If you’ve been diagnosed with cancer and are interested in getting a second opinion of your diagnosis or treatment options, call us or chat online with a member of our team.