Low neutrophils can generally be detected by routine blood tests, and the causes are mostly related to physical damage, chemical damage, infectious factors, drug factors, blood diseases or autoimmune diseases, etc. It is recommended that patients promptly consult their doctors and improve other tests, and take timely treatment measures if diseases exist: 1. The physical factors such as long-term exposure to X-rays, gamma rays, radionuclides, etc. can cause certain damage to the body and can also cause low neutrophils. You should stay away from these factors and take appropriate treatment for the damage caused; 2. chemical damage: long-term exposure to chemical substances such as benzene, lead, mercury, etc., can also lead to low white blood cells. Viral infections such as influenza, chickenpox, rubella, hepatitis virus and cytomegalovirus can also have low neutrophils, and some protozoan infections such as malaria and black fever can also have low neutrophils. Usually need to follow medical advice to apply antibiotics or antiviral, anti-protozoal drugs for treatment, to promote neutrophil recovery; 4, drug factors: such as chloramphenicol, sulfonamides, and some of the treatment of diabetes drugs, anti-tumor drugs and anti-thyroid drugs can cause low white blood cells and neutrophils, for the application of such drugs for treatment of patients can ask the doctor whether the need to stop; 5, blood disease 5. Blood diseases: such as megaloblastic anemia, aplastic anemia, hemophagocytic syndrome, paroxysmal sleep hemoglobinuria, and bone marrow metastases can cause low white blood cells and neutrophils, accompanied by low platelets and red blood cells. If necessary, immunotherapy or blood transfusion can be performed. 6. Autoimmune diseases: diseases such as systemic lupus erythematosus can produce autoantibodies that lead to low neutrophils and white blood cells, so the patient can go to the Rheumatology and Immunology Department and apply immune-regulating drugs for treatment as prescribed by the doctor. 7. 7. Other: various causes of spleen enlargement and its function, such as partial lymphoma, phagocytic syndrome, portal cirrhosis, etc., also often appear low white blood cells, should be treated for the original disease, and hormonal drugs or drugs to improve liver function can be applied as prescribed.