Absolute Neutrophil Count, Automated

This test measures the number of neutrophils, a type of white blood cell that is central to fighting bacterial and fungal infections. It is reported as an absolute count and is typically produced as part of a complete blood count with differential.

Automated hematology analyzers classify and count cells using technologies such as electrical impedance and flow cytometry. The result reflects how many neutrophils are circulating in a given volume of your blood at the time of the draw.

Your neutrophil count helps your care team assess your ability to fight infections. A low count, often called neutropenia, can increase the risk of serious infection. A high count can occur with infections, inflammation, significant stress, or from certain medications such as corticosteroids.

Clinicians order this test when you have fever or signs of infection, before and during cancer treatments, when monitoring medicines that can affect the bone marrow, or when investigating autoimmune or bone marrow conditions. It is also followed during treatment with colony-stimulating factors that raise white blood cell production.

Results are interpreted alongside your symptoms, medical history, and other parts of the complete blood count. Reference intervals vary with age, and trends over time are often more informative than a single value. Some healthy individuals have lower baseline counts, and babies and children can have patterns that differ from adults.

If your count is low and you develop fever, chills, or new symptoms, contact your clinician promptly. If it is high but you feel well, it may reflect a temporary response to infection, stress, or medication. Persistently abnormal results may lead your clinician to repeat testing, review medicines, look for infections or inflammation, or, if needed, order additional tests of bone marrow function.