Understanding neutropenia
Low white blood cell counts and infection risk
The short version
Neutropenia means a lower-than-normal level of neutrophils, a white blood cell that helps fight infection. It's a common, usually temporary chemotherapy side effect, and can raise infection risk during the lowest-count period.
Neutropenia describes a lower-than-normal count of , the white blood cells most responsible for fighting bacterial infection. Many chemotherapy drugs can temporarily lower this count, typically reaching its lowest point ("nadir") one to two weeks after an infusion before recovering.
Fever during neutropenia is an emergency
A fever (often defined as 100.4°F/38°C or higher) during a period of low white blood cell counts can signal a serious infection and needs immediate medical attention — call your care team's after-hours line or go to the emergency room right away, even if you feel otherwise okay.
- Wash hands frequently and avoid people who are sick
- Follow any specific food-safety precautions your team gives you
- Take your temperature if you feel unwell, and know your team's fever threshold and after-hours number
Questions you may want to ask
When during my cycle are my counts likely to be lowest?
What is my fever threshold, and who do I call?