Leukocytes 9.87×10⁹/L is within the normal range of values because the normal value is (4.0~10.0)×10⁹/L. Although leukocytes 9.87×10⁹/L is within the normal range, the value is close to the limit of the reference value, and it is necessary to see whether there is a bacterial infection at the same time. If there are no other uncomfortable symptoms, no treatment can be done and observation is recommended. Leukocytes have a certain ability of chemotaxis and migration, and can move from intravascular to extravascular and from extravascular to intravascular. Therefore, leukocytes not only exist in blood and lymph, but also widely exist in tissues other than blood vessels and lymphatic vessels. Leukocytes can secrete a variety of cytokines, such as interleukin, interferon, tumor necrosis factor, etc. to participate in the regulation of inflammation and immune response. Therefore, if you have any uncomfortable symptoms, please consult a doctor in time.