An absolute neutrophil count (ANC) blood test measures the number of neutrophils in a person’s blood. Neutrophils are a type of white blood cell that help the body fight infections by attacking bacteria and other foreign substances. The ANC test is often used to monitor the immune system during chemotherapy or other medical treatments that can lower a person’s white blood cell count.

The ANC is calculated by multiplying the total white blood cell count by the percentage of neutrophils in the blood. The normal range for the ANC varies depending on the laboratory, but generally falls between 1,500 and 8,000 cells per microliter of blood (cells/mcL).

Low ANC levels, also known as neutropenia, can increase the risk of infections and make it more difficult for the body to fight off infections. Causes of neutropenia can include chemotherapy, radiation therapy, certain medications, and certain medical conditions such as aplastic anemia or autoimmune disorders. Treatment for neutropenia may involve addressing the underlying cause and, in some cases, taking medications to stimulate white blood cell production.

High ANC levels, also known as neutrophilia, can indicate the presence of an infection or inflammation in the body. Causes of neutrophilia can include bacterial infections, certain types of leukemia, and inflammatory conditions such as rheumatoid arthritis. Treatment for neutrophilia may involve addressing the underlying cause of the elevated ANC levels.