Low CD8+ T-cells, it is recommended to carry out relevant examinations in time, such as bone puncture or pathogenetic examination, etc., in order to clarify the cause of the disease and actively treat it. 1. Common viral infection: If a foreign virus attacks the human body and causes a viral infection, a decrease in CD8+ T cells may occur. In this case, antiviral drugs such as acyclovir can be used under the guidance of a doctor; 2. Immunity-related diseases: after excluding viral infection, one should be alert to the presence of immunodeficiency diseases, such as leukemia, aplastic anemia, etc.; one should also be alert to the presence of malignant tumors in the body, which lead to a decrease in immune cells CD8+ T cells. In this case, according to the doctor’s diagnosis to actively cooperate with the treatment. Such as acute leukemia to be a sugar cytidine and other drugs chemotherapy. 3. If there is exogenous radiation therapy in the previous period, the radiation will affect the hematopoietic function of the bone marrow, and the situation of low CD8+ T cells may also occur. It is necessary to regularly monitor the changes of indicators, or perform bone puncture to check the hematopoietic condition of bone marrow. Specific diagnosis and treatment should be carried out under the guidance of physicians.