What If You Get a Cold During Chemo?

People who are receiving chemotherapy are more likely to get sick with colds and influenza (the flu) because the treatments weaken their immune systems. If they do get sick with these infections, it can lead to serious, if not life-threatening, illness. Therefore, they need to be aware of the signs and symptoms of colds, flu, and other infections.

This article will discuss how to deal with a cold, the flu, or another infection while undergoing chemotherapy treatments.

Preventing Colds, Flu, and Infections During Chemotherapy

Verywell / Ellen Lindner

How Does Chemotherapy Increase the Risk of Colds and Flu?

Chemotherapy weakens the immune system, making people who are undergoing treatment more susceptible to colds, the flu, or other infections.

Normally, the cells in your body grow and die in a controlled way. Cancer cells keep growing without stopping. Chemotherapy works by killing the cancer cells, stopping them from spreading, or slowing their growth.

However, chemo cannot differentiate cancer cells from healthy cells, which means that it can also harm healthy cells. When this happens, people experience certain side effects.

Chemo can damage the bone marrow, which reduces its ability to produce white blood cells. Your body needs white blood cells to help fight off infections. Neutropenia, a low level of a type of white blood cells called neutrophils, can occur in people getting chemotherapy.

When the body does not have enough white blood cells, it is more vulnerable to viruses and other pathogens.

Colds and Chemotherapy

When you are receiving chemotherapy, it's important to be on the lookout for symptoms of an infection—even a simple cold.

Some of the most common signs and symptoms of a cold include:

  • Runny or stuffy nose
  • Congestion
  • Cough
  • Sore throat
  • Sneezing
  • Itchy or watery eyes
  • Fever (rare in adults; more common in children)

The Flu and Chemotherapy

You might also be more likely to catch the flu when you are receiving chemo. The signs and symptoms of the flu can include:

  • Fever
  • Exhaustion
  • Headaches
  • Congestion
  • Coughing
  • Aches and pains
  • Chills
  • Vomiting and diarrhea (though these symptoms are not common)

You may have some of these symptoms if you have a cold, but there are some differences between cold and flu symptoms that you should be aware of.

  • Abrupt onset of symptoms

  • You will be so sick that getting out of bed will be difficult

  • Any symptoms that you do experience will be severe

  • Gradual onset of symptoms

  • You will feel unwell but can still function throughout the day

  • Symptoms will often be mild and manageable

The Flu vs. COVID-19

You are also at a higher risk of contracting COVID-19 if you are undergoing chemo. It's important to know the signs and symptoms of COVID, as well as how it is different from other respiratory infections.

The flu and COVID-19 are both caused by viruses, but not the same one. The flu is caused by the influenza viruses, and COVID-19 is caused by the SARS-CoV-2 virus.

Both infections can cause a fever, body aches, and cough. COVID-19 can also cause loss of sense of smell and taste, which is considered a hallmark symptom.

When to Call Your Doctor

Infections, including a cold, the flu, and COVID, can be life-threatening for people with weak immune systems. If you have symptoms of an infection while you are receiving chemotherapy, call your doctor as soon as you start feeling unwell.

Managing an Infection

A cold or flu infection can be serious if you are having chemotherapy. Treating a cold, the flu, or another infection is different for people receiving chemo because they cannot take certain medications.

Many people first reach for cold and flu remedies at their local pharmacies to soothe a cold, but if you're having chemo, you should talk to your doctor before taking any over-the-counter (OTC) medications.

The treatment that you receive for an infection while you're undergoing chemotherapy will depend on the cause of the infection and how severe your symptoms are.

If you have a bacterial infection, your doctor might prescribe an antibiotic. If the infection is caused by a virus or a fungus, your doctor might give you an antiviral or antifungal medication.

Treatment will typically last between seven and 14 days. If you do not respond to treatment within three to five days, your doctor might give you more medication or a different medication.

Preventing Colds, Flu, and Infections

If you are undergoing cancer treatments, there are steps you can take to prevent colds, the flu, and other infections.

Practice Good Hygiene

Practicing good hygiene is important for anyone, but it's especially crucial for those undergoing chemotherapy. To ensure that you are keeping yourself protected from infections, you should:

  • Wash your hands frequently (or cleanse them with a hand sanitizer if soap and water are not available).
  • Bathe or shower every day.
  • Keep a close eye on any injury sites or cuts on the body.
  • Wash any cut (even a small one) right away, and keep it covered with a bandage for the first few days to keep it clean.
  • Avoid emptying litter boxes, cleaning pet cages, or grooming your pet.
  • Avoid swimming in ponds, lakes, or rivers.

Activity and Rest

You should take care of your general health by eating well, getting plenty of rest, and exercising regularly if you are able to.

Research has shown that sleep disturbances are common in people getting chemotherapy. You can get better sleep by practicing calming and relaxing exercises (such as yoga) and avoiding naps during the day even if you feel tired.

You should avoid anyone you think may have a cold, the flu, or another type of infection as well as avoid large indoor crowds.

Food and Food Safety

It is common for people receiving chemotherapy to experience changes with their appetite. Being full faster, feeling nauseated, and experiencing a change in the way food tastes all affect how you eat.

However, to keep your general health as good as it can be while you are undergoing chemo, make sure you're getting as many nutrients and vitamins as possible from your diet.

People undergoing chemotherapy are also more likely to catch a foodborne illness than the general population, but studies have shown that roughly half of cancer patients are aware of this risk.

According to the Centers for Disease Control and Prevention (CDC), there are several ways you can reduce the risk of contracting a foodborne illness.

Good food safety practices you can implement at home include:

  • Cleaning your hands, work surfaces, and fruits and vegetables thoroughly before, during, and after preparing food
  • Keeping meat, poultry, eggs, and seafood separate from ready-to-eat foods, and using separate cutting boards for meat and other foods
  • Cooking food to the right internal temperature and checking the temperature using a food thermometer
  • Keeping your fridge at 40 degrees Fahrenheit or below and putting leftovers in the fridge within two hours of cooking

You should also refrain from sharing food or eating utensils with other people. If you get your tap water from a well, make sure it does not have any contaminants. You may want to purchase a home faucet filter or drink bottled water while you are in treatment.

Oral Health

Chemotherapy can cause issues with oral health, such as oral sores, tooth decay, and infections. It is important to monitor your oral health during chemotherapy to avoid infections.

It is recommended that you use an extra-soft toothbrush. You should brush after every meal and at bedtime, as well as floss once a day. Consider using an antibacterial mouthwash to rinse your teeth and gums two to four times a day.

Try to schedule your dental appointments for when your white blood cell count is highest to help reduce the risk of infection.

Get Vaccinated

During chemotherapy, your doctor may recommend that you get vaccinated against the flu. Some studies have found that it can help the body build up protection against the flu and help you avoid the illness while you are in treatment.


People who are going through chemotherapy treatments for cancer are more susceptible to getting infections. They are also more likely to have severe adverse effects if they become sick with a cold, the flu, or another infection.

To avoid getting sick while undergoing chemo treatments, practice good hygiene, eat well, exercise regularly, and talk to your doctor about getting a flu vaccine.

A Word From Verywell

Getting an infection, even a simple cold, while you are undergoing chemotherapy can be life-threatening. The best way to protect yourself is by taking preventive measures. If you notice any signs of an infection while you are undergoing chemotherapy, call your doctor right away.

Frequently Asked Questions

  • Will chemo be delayed if I have a cold?

    If you develop a cold or the flu during chemotherapy, your treatment might be delayed while your doctors focus on treating the infection. Patient safety is important during chemotherapy, and doctors do not want to risk making the infection worse by continuing a treatment that further weakens your immune system.

  • Are colds dangerous for chemo patients?

    Getting a cold while you are undergoing chemotherapy treatment can be life-threatening. If you come down with a cold during chemotherapy, you should call your doctor as soon as possible. If you cannot reach your healthcare team, you may need to visit the emergency department at your nearest hospital to get appropriate diagnosis and treatment.

  • How can I boost my immune system during chemo?

    There are several ways that you can protect your immune system during chemotherapy. Eating a nutritious diet with immune-boosting foods and exercising as much as you can during your treatment may help boost immune function. Studies have shown that regular exercise can strengthen the immune system in cancer patients.

  • What happens if you get an infection during chemotherapy?

    If you get an infection during chemotherapy, your body is unable to fight it off as well because your immune system is weakened. The infection can lead to more severe symptoms and worse outcomes, which is why it's important that you let your doctor know right away if you start to feel sick.

14 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Angelica Bottaro
Angelica Bottaro is a professional freelance writer with over 5 years of experience. She has been educated in both psychology and journalism, and her dual education has given her the research and writing skills needed to deliver sound and engaging content in the health space.