A spleen of 121mm x 41mm is considered slightly large, and a normal spleen is 10-12cm long, 6-8cm wide, and 3-4cm thick. There are reasons for the large spleen, mostly caused by infection, bruising, hyperplasia, etc.. 1. Infectious splenomegaly: common diseases include viral hepatitis, typhoid fever, paratyphoid fever, schistosomiasis and so on. 2. Siltation splenomegaly: common causes are cirrhosis, cardiogenic cirrhosis due to chronic heart failure, portal or splenic vein thrombosis, constrictive pericarditis, chronic congestive splenomegaly and so on. 3. Proliferative splenomegaly: common diseases are hematological diseases, such as leukemia, malignant lymphoma, hemolytic anemia and so on. 4. Others: splenic cyst, dermatomyositis, nodular polyarteritis, etc. can also lead to splenomegaly. The causes of enlarged spleen are complicated, patients should look for the causes under the guidance of doctors and actively standardize the treatment.