Low neutrophils, a small number of patients with drug damage or bone marrow injury, can be self-healing after the release of injury, most need active treatment, can not be self-healing. In adults, neutropenia is recognized when the peripheral blood neutrophil count is less than 2.0 x 10^9/l, and granulocyte deficiency when it is less than 0.5 x 10^9/l. The main causes of neutropenia include decreased production, destruction or excessive depletion, and abnormal cell distribution. Reduced production is caused by radiation, cellular drugs on the bone marrow to cause some damage to the bone marrow, after lifting the bone marrow damage factors, bone marrow function can be recovered on its own, and granulocytopenia can be cured by itself. Bone marrow infiltration of tumor cells, lack of hematopoietic raw materials caused by granulocyte maturation disorders and other factors can also cause reduced granulocyte production. Systemic lupus erythematosus, severe infections, hypersplenism can cause excessive granulocyte depletion or destruction. These granulocytopenias, which require treatment, do not resolve spontaneously. There are also abnormalities in the distribution of granulocytes, such as severe malnutrition and severe bacterial infections, which also require aggressive treatment and cannot be cured. Low neutrophils, it is recommended to seek medical attention to clarify the cause of the disease and standardize the treatment.