Low neutrophils are prone to immune deficiency and recurrent infections. Neutrophil count below 0.5×10^9/L is more dangerous and needs active treatment, such as hormone therapy. 1. Neutrophils are a kind of white blood cells, with phagocytosis and bactericidal effect, the normal value is (1.8~6.3)×10^9/L, when lower than 1.5×10^9/L, consider neutropenia, the common cause of viral infections, such as influenza, chemotherapy drugs side effects, etc., the influenza treatment can be taken to take antiviral oral solution and so on. 2. When it is lower than 0.5×10^9/L, it is considered as granulocyte deficiency, and the common causes are bacterial infections such as typhoid fever, sepsis, and rickettsial infections such as typhus, etc. At this time, it is necessary to actively treat the primary disease. When the blood routine shows low neutrophils, it is recommended to go to the hospital in time, complete the examination, clarify the cause of the disease, and carry out standardized treatment under the guidance of the doctor, and the medication should be taken in accordance with the doctor’s instructions.