What does it mean to have a low neutrophil count?

A low neutrophil count refers to an absolute neutrophil count below the normal lower limit as detected in a complete blood count. The main causes of neutropenia are as follows: 1. Production defects: Cytotoxic drugs, chemical toxins, ionizing radiation, and other chemical and physical factors are common causes of neutropenia. These can directly damage hematopoietic stem cells, progenitor cells, or the bone marrow microenvironment, leading to pancytopenia. In addition, diseases that affect hematopoietic stem cells or impaired differentiation and maturation of cells due to various causes can also result in neutropenia; 2. Excessive consumption: Conditions such as autoimmune diseases, infections, or sepsis may lead to excessive consumption of granulocytes, resulting in granulocytopenia; 3. Abnormal distribution: A large number of granulocytes shift into the marginated pool, causing a relative reduction in the circulating pool, making them undetectable during cell counting; alternatively, granulocytes may be retained in other parts of the circulating pool, leading to reduced neutrophil counts in peripheral blood.