Absolute neutrophil value of 1.69×10⁹/L is a mild decline, which may be caused by the effect of drugs, which is a normal phenomenon, and can also be caused by infections, blood diseases and other illnesses, which is an abnormal phenomenon. 1. Drug effects: acetaminophen, cephalosporin, captopril and many other drugs have the adverse effect of causing neutrophil decline, need to be evaluated by the doctor whether to stop the drug, and regularly monitor changes in indicators. 2. Infection: common in virus, typhoid fever, some protozoa and other infections, need to identify the infectious agent, according to the pathogen selection of drug treatment, such as viral infections often choose acyclovir and other drugs treatment. 3. Blood diseases: aplastic anemia, paroxysmal sleep hemoglobinuria, leukemia, etc., need to carry out bone marrow aspiration and other tests to make it clear, generally need to use drugs for the treatment of the cause, such as acute myeloid leukemia to be a cytarabine and other drugs such as chemotherapy. The normal reference range of absolute neutrophil value is (1.8~6.3)×10⁹/L, and the reference range varies slightly according to different medical institutions. Clinically, when the absolute neutrophil value is lower than 1.5×10⁹/L, it is called granulocytopenia, and when the absolute value is lower than 0.5×10⁹/L, it is called granulocyte deficiency. L is called granulocyte deficiency. Neutrophils 1.69 × 10⁹ / L, is a mild decline, there are many reasons, it is recommended to consult a doctor in a timely manner, under the guidance of the physician to determine the specific cause.