An abnormally low count of a type of white blood cell called neutrophils.

Neutropenia (noo-troe-PEE-nee-uh) is an abnormally low count of neutrophils, a type of white blood cell. It can be caused by diseases that damage the bone marrow, infections or certain medicines. Cancer chemotherapy is a common cause of neutropenia.

Neutropenia usually produces no symptoms. People often only find out when they've had blood tests done for other reasons.

People who have neutropenia are vulnerable to infections. To reduce the risk of infection, stay up to date on vaccinations, avoid large crowds, and wash hands regularly and thoroughly.