Frequently Asked Questions

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What is a low white blood cell count?

Chemotherapy is a commonly used treatment for cancer. These powerful cancer-fighting drugs work by killing the fastest-growing cells in the body—both good and bad. This means that along with killing cancer cells, your healthy white blood cells, called neutrophils, are killed too.

When the number of neutrophils is reduced, a condition called neutropenia occurs and your risk of getting an infection is increased. The period of time beginning 7 – 12 days after you finish each chemotherapy dose—and possibly lasting up to one week—is when you have the fewest white blood cells in your body. Because of this, it will be extra hard for your body to fight off germs during this time. This period of time is often called your nadir, meaning “lowest point.” This is when you are more likely to develop neutropenia. This period varies slightly depending upon the chemotherapy drug, or combination of drugs, used. Your doctor and/or nurse will let you know exactly when your white blood cell count is likely to be at its lowest.

You should watch very carefully for signs and symptoms of infection during this time. During these high-risk days, you should take your temperature any time you feel warm, flushed, chilled, or not well.

What is an infection?

An infection occurs when germs enter a person’s body and multiply, causing illness, organ and tissue damage, or disease. Some common germs and infections include the following:

  • Bacteria: Very small microorganisms. Some types of bacteria enter the human body from the air, water, soil, or food, and can cause infections and disease. Common bacterial infections include pneumonia, bronchitis, and ear infections.
  • Virus: A very simple microorganism that may cause illness or disease. Viral infections are passed on from other people. Common viral infections include the common cold, herpes, and flu.
How does the body normally resist infections?

Your immune system helps your body protect itself from getting an infection from germs. Cancer and chemotherapy can damage this system, reducing your numbers of infection fighting white blood cells and making it harder for your body to fight infection from germs.

Who is at risk for getting an infection?

There are certain factors that may make it more likely for you to develop serious infections while your white blood cell count is low:

  • You are 65 years or older.
  • You are female.
  • You are unable to take care of yourself without assistance and are bed-bound.
  • You have lost a lot of weight in a short time (unintentional weight loss).
  • You have another condition that makes it more difficult to fight off infections (i.e., diabetes, kidney disease, high-blood pressure, congestive heart failure, an auto–immune disease, liver dysfunction, chronic bronchitis, or emphysema).
  • You have a type of cancer that affects the blood or lymph nodes (for example, leukemia).
  • Your cancer has spread to other parts of the body.
  • You have had chemotherapy or radiation in the past.
  • The chemotherapy that you are receiving is strong. You are receiving more than one chemotherapy drug. The stronger the chemotherapy, the more of your white blood cells will be killed, making your immune system weaker. Strong chemotherapy may also make your immune system weaker for longer, which also increases your risk of getting an infection.
  • Your doctor or nurse has told you have a low white blood cell count in the past.

To find out more about the risks of developing a low white blood cell count from your chemotherapy, speak with your doctor or nurse.

What are the signs and symptoms of an infection?

Many times,may be our body’s only sign of an Infections duringcan be life threatening and may delay futuretreatments. Because your whiteis low, your body may not be able to fight theon its own.

This is why it’s very important that you call your doctor immediately, even if it is in the middle of the night, if you have a temperature of 100.4ºF (38ºC) or higher for more than 1 hour, or a one-time temperature of 101ºF (38.3ºC) or higher.

You should also be sure to do the following:

  • Keep a working thermometer in a convenient location and know how to use it.
  • Take your temperature any time you feel warm, flushed, chilled, or not well.
  • Be aware of when you are at highest risk ofdue to a low white Your doctor and/or nurse will let you know exactly when your whitecan be expected to be at its lowest. This period is sometimes referred to as the which means “lowest point.”
  • Keep your doctor's phone numbers with you at all times. Make sure you know what number to call during their office hours and what number to call after hours. If you have aduring a time when the office is closed, DO NOT wait until the office reopens before you call.
  • If you have to go to the emergency room, it’s important that you tell the person checking you in that you are a cancer patient undergoing This is because if you have anyou shouldn’t sit in the waiting room for a long time. Infections can get very serious the longer they go untreated,

While developing ais the most seriousand should be treated as an emergency, there are several other signs or symptoms you should be aware of that may indicate you have an infection:

  • Chills and sweats
  • Change in cough or new cough
  • Sore throat or new mouth sore
  • Shortness of breath
  • Nasal congestion
  • Stiff neck
  • Burning or pain with urination
  • Unusual vaginal discharge or irritation
  • Increased urination
  • Redness, soreness, or swelling in any area, including surgical wounds and ports
  • Diarrhea
  • Vomiting
  • Pain in the abdomen or rectum
  • New onset of pain
  • Changes in skin, urination, and mental status

If you experience any of these signs or symptoms you should call your doctor immediately.

What should you do if you think you have an infection?

Contact your doctor immediately, even if it is the middle of the night. Do not wait until the next 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.

How can I reduce my risk for infection?

Hand washing is the number one way to prevent infections. This should include you, all members of your household, your doctors, nurses and anyone that comes around you. Don’t be afraid to ask people to wash their hands.

Washing your hands with soap and water is the most effective, but it's OK to use an alcohol-based hand sanitizer if soap and water are not available.

You should wash your hands:

  • Before, during, and after cooking food
  • Before you eat
  • After going to the bathroom
  • After changing diapers or helping a child to use the bathroom
  • After blowing your nose, coughing, or sneezing
  • After touching your pet or cleaning up after your pet
  • After touching trash
  • Before and after treating a cut or wound or caring for your catheter, port, or other access device.


You should also do the following:

  • Protect your skin from scrapes and cuts
  • Maintain good oral and body hygiene practices
  • Practice proper wound care
  • Use disinfectants to keep your household surfaces free of germs
  • Avoid situations where you might come into close contact with people who may be sick
  • Use disinfectants to keep your household surfaces free of germs
  • Protect your skin from direct contact with pet bodily waste (urine or feces)
Are there certain foods that can cause an infection?

There are things that you need to be aware of when choosing the types of food you plan to eat. Remember that your cancer, or the medicine that you are taking to treat your cancer, may increase your risk of infection.

To protect yourself, avoid the following:

  • Undercooked or raw meat or eggs.
  • Raw or unpasteurized products (check the label on the dairy products you buy such as milk and cheese, and fruit juices, to ensure they are pasteurized). Raw and unpasteurized products contain bacteria that may cause you to become ill.
  • Unwashed fruits or vegetables.
How can I learn about my risk of getting an infection?

Complete the risk assessment tool to learn about your risk for developing a low white blood cell count during cancer treatment.

Education Materials

CDC created a variety of resources for patients and healthcare providers, including a quick reference sheet, fact sheets, posters, and videos.

"I never thought seriously about the risk of infection until I was hospitalized and unable to fight a fever. It’s so important to understand what steps you can take to help protect yourself."Donna Deegan, News AnchorBreast Cancer Survivor 

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