What it is: A neutrophil count measures the number of neutrophils, the most abundant type of white blood cell and the immune system's first responders against bacterial and fungal infection, typically as part of a CBC with differential.
Why it's ordered: Ordered alongside a CBC with differential to help evaluate suspected bacterial infection, inflammation, or bone marrow function, including during chemotherapy monitoring.
What it detects: Neutrophils rise (neutrophilia) with bacterial infection, inflammation, or stress; they fall (neutropenia) with certain infections, autoimmune conditions, or bone marrow suppression from chemotherapy, raising infection risk.
Collection & prep: A standard blood draw from a vein in the arm, as part of a CBC with differential. No special preparation is needed.
Results:
High – often reflects bacterial infection or acute inflammation
Low – raises infection risk; can result from certain infections, autoimmune disease, or chemotherapy
Normal – typically 40–60% of total white blood cells
Possible complications of low neutrophils: Significant neutropenia substantially increases the risk of serious infection, so low counts — especially during chemotherapy — are closely monitored and may prompt precautions against infection exposure.
Statements made in the Clinical Manual have not been evaluated by the FDA. The products mentioned are not intended to diagnose, treat, cure or prevent any disease.
