Granulocyte deficiency is a decrease in granulocytes, associated with decreased granulocyte production, impaired maturation, and excessive depletion, and can present with high fever and headache. Granulocyte deficiency is a relatively common emergency in internal medicine. In general, granulocytopenia usually refers to neutropenia. 1. Aplastic anemia, acute leukemia, infection, tumor bone marrow infiltration can lead to reduced granulocyte production; 2. Vitamin B12 or folic acid deficiency can lead to impaired granulocyte maturation; 3. Systemic lupus erythematosus, sepsis, severe infections, etc. can lead to excessive granulocyte consumption. All of these factors can lead to the occurrence of granulocyte deficiency. Patients with granulocyte deficiency can have high fever, chills, fatigue, muscle or joint pain, headache, loss of appetite and other systemic symptoms. Specific treatments for the cause of the disease, such as aplastic anemia caused by granulocyte deficiency, need to be oral cyclosporine or allogeneic hematopoietic stem cell transplantation therapy. It is recommended to go to the hospital in time to find out the cause and receive regular treatment under the guidance of the physician if the above symptoms occur.