The spleen is the largest lymphoid organ and an important immune organ in the body. Traumatic splenic rupture, hypersplenism, occupying lesions of the spleen and hematopoietic disorders are the main indications for splenectomy. Splenectomy can easily lead to effects on the immune system and blood components, with manifestations such as decreased immunity and increased platelets, and in severe cases or in the elderly, even easy to develop blood clots. I. Effects: 1. Immune system: the spleen is an important immune organ in the human body, and after resection, it may lead to partial absence of spleen-related immune functions and relative weakening of humoral immune functions, which may cause a certain degree of reduction in body immunity; 2. Blood system: the spleen has a certain blood storage function, which transports blood throughout the body when in a stressful state and increases blood volume. The spleen may have secondary thrombocytosis, and more serious cases may have thrombocytosis. The sequelae: 1, immune deficiency: after splenectomy will affect the immune function, the weaker people may have long-term immune deficiency after splenectomy, prone to infectious diseases, or often dizziness, headache, weakness, elevated body temperature and other manifestations; 2, abdominal fluid: some patients may have abdominal fluid after splenectomy, which can be diagnosed by ultrasound, CT, etc.; 3, bleeding and anemia: the spleen is responsible for blood storage, after resection, some patients with weaker constitution may have bleeding, anemia, malnutrition, etc.; 4, thrombosis: after splenectomy, secondary thrombocytosis may easily appear, and older people or patients with pre-existing thrombotic diseases are more likely to have increased risk of thrombosis.