Neutropenia has no specific symptoms, and the symptoms are mostly related to the primary causes of neutropenia, which include physical factors, emotional excitement, infections, inflammation, tumors, blood diseases, drugs and poisons. 1. Symptoms: Patients with neutropenia do not have specific clinical symptoms. Temporary obstruction of capillaries may occur, which temporarily reduces the local blood flow, thus leading to local ischemia, such as leading to myocardial reperfusion injury and infarction. 2.Etiology (1) Physical factors: physical activity, pregnancy, childbirth, cold or hot stimuli, etc. (2) Emotional agitation: anxiety, panic, excitement, etc. (3) Infection: many acute bacterial infections can cause neutrophilia, such as Streptococcus pneumoniae infection. (4) Inflammation: rheumatic fever, vasculitis, rheumatoid arthritis, etc. (5) Tumor: stomach cancer, bronchial lung cancer, breast cancer, etc. (6) Blood diseases: myeloproliferative syndrome, malignant lymphoma, multiple myeloma, etc. (7) Drugs and poisons: acetylcholine, epinephrine, benzene, lithium, lead, etc., of which lithium elevates neutrophils most obviously. Patients with neutrophilia should consult the doctor in time to find out the cause and standardize the treatment.