The spleen is an important organ of the human body and plays an important role in the body’s blood system and immune system. 1. Blood system: the spleen can destroy and remove senescent red blood cells; it can store blood, and can be used as a reserve blood bank when the blood volume is sufficient; when the body is in ischemic state, the spleen can release part of the blood to replenish the blood volume; it also has a hematopoietic function, and participates in the hematopoiesis of bone marrow, and can repair the platelets. 2. Immune system: the spleen stores a large number of stress leukocytes, which participate in the body’s immune response and phagocytosis of disease-causing bacteria; the spleen is the largest lymphoid organ in the human body, which has the function of producing lymphocytes and immunoglobulin, and participates in the body’s cellular immune response to establish the body’s immune barrier. Therefore, the spleen is important to the human body. In order to detect spleen diseases in time, it is recommended to have regular medical checkups and early formal treatment after detection.