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.

Program Materials

To help raise awareness about the importance of preventing infections in cancer patients, the Centers for Disease Control and Prevention (CDC) created a variety of resources for patients as well as for use in provider’s offices, patient rooms, and work areas. These resources include posters, fact sheets, post cards, videos, and more. View Materials >

"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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